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Honey is a sweet and
viscous The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the in ...
substance made by several bees, the best-known of which are honey bees. Honey is made and stored to nourish bee colonies. Bees produce honey by gathering and then refining the
sugar Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or do ...
y secretions of plants (primarily floral nectar) or the secretions of other insects, like the honeydew of aphids. This refinement takes place both within individual bees, through regurgitation and enzymatic activity, as well as during storage in the hive, through water evaporation that concentrates the honey's sugars until it is thick and viscous. Honey bees stockpile honey in the
hive A hive may refer to a beehive, an enclosed structure in which some honey bee species live and raise their young. Hive or hives may also refer to: Arts * ''Hive'' (game), an abstract-strategy board game published in 2001 * "Hive" (song), a 201 ...
. Within the hive is a structure made from wax called honeycomb. The honeycomb is made up of hundreds or thousands of
hexagonal In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°. Regular hexagon A '' regular hexagon'' has ...
cells, into which the bees regurgitate honey for storage. Other honey-producing species of bee store the substance in different structures, such as the pots made of wax and
resin In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on nat ...
used by the stingless bee. Honey for human consumption is collected from wild bee colonies, or from the hives of domesticated bees. The honey produced by honey bees is the most familiar to humans, thanks to its worldwide commercial production and availability. The husbandry of bees is known as beekeeping or apiculture, with the cultivation of stingless bees usually referred to as meliponiculture. Honey is sweet because of its high concentrations of the monosaccharides fructose and
glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...
. It has about the same relative sweetness as sucrose (table sugar).National Honey Board
"Carbohydrates and the Sweetness of Honey"
. Last accessed 1 June 2012.
Oregon State Universit

Retrieved 1 June 2012.
One standard tablespoon (15 mL) of honey provides around of food energy. It has attractive chemical properties for baking and a distinctive flavor when used as a sweetener. Most
microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in old ...
s cannot grow in honey and sealed honey therefore does not spoil. Samples of honey discovered in archaeological contexts have proven edible even after thousands of years. Honey use and production has a long and varied history, with its beginnings in
prehistoric times Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use ...
. Several cave paintings in
Cuevas de la Araña The Coves de l'Aranya (in original Catalan language, known in English as the Spider Caves and in Spanish Cuevas de la Araña) are a group of caves in the municipality of Bicorp in València, eastern Spain. The caves are in the valley of the river ...
in
Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...
depict humans foraging for honey at least 8,000 years ago. While ''Apis melifera'' is an Old World
insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...
, large-scale meliponiculture of New World stingless bees has been practiced by Mayans since
pre-Columbian In the history of the Americas, the pre-Columbian era spans from the original settlement of North and South America in the Upper Paleolithic period through European colonization, which began with Christopher Columbus's voyage of 1492. Usually, ...
times.


Formation


By honeybees

Honey is produced by bees who have collected nectar or honeydew. Bees value honey for its sugars, which they consume to support general metabolic activity, especially that of their flight muscles during foraging, and as a food for their larvae. To this end bees stockpile honey to provide for themselves during ordinary foraging as well as during lean periods, as in
overwintering Overwintering is the process by which some organisms pass through or wait out the winter season, or pass through that period of the year when "winter" conditions (cold or sub-zero temperatures, ice, snow, limited food supplies) make normal act ...
. During foraging bees use part of the nectar they collect to power their flight muscles. The majority of nectar collected is not used to directly nourish the insects but is instead destined for regurgitation, enzymatic digestion, and finally long-term storage as honey. During cold weather or when other food sources are scarce, adult and
larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...
l bees consume stored honey, which is many times as energy-dense as the nectar from which it is made. National Honey Board After leaving the hive a foraging bee collects sugar-rich nectar or honeydew. Nectar from the flower generally has a water content of 70 to 80% and is much less viscous than finished honey, which usually has a water content around 18%. The water content of honeydew from aphids and other
true bugs Hemiptera (; ) is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from to aroun ...
is generally very close to the sap on which those insects feed and is usually somewhat more dilute than nectar. One source describes the water content of honeydew as around 89%. Whether it is feeding on nectar or honeydew, the bee sucks these runny fluids through its proboscis, which delivers the liquid to the bee's proventriculus, also called the honey stomach or honey crop. This cavity lies just above its food stomach, the latter of which digests pollen and sugars consumed by an individual honeybee for its own nourishment. In ''
Apis mellifera The western honey bee or European honey bee (''Apis mellifera'') is the most common of the 7–12 species of honey bees worldwide. The genus name ''Apis'' is Latin for "bee", and ''mellifera'' is the Latin for "honey-bearing" or "honey carrying", ...
'' the honey stomach holds about 40 mg of liquid. This is about half the weight of an unladen bee. Collecting this quantity in nectar can require visits to more than a thousand flowers. When nectar is plentiful it can take a bee more than an hour of ceaseless work to collect enough nectar to fill its honey crop. Salivary enzymes and proteins from the bee's hypopharyngeal gland are secreted into the nectar once it is in the bee's honey stomach. These substances begin cleaving complex sugars like sucrose and
starches Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets, ...
into simpler sugars such as
glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...
and fructose. This process slightly raises the water content and the acidity of the partially digested nectar. Once filled, the forager bees return to the hive. There they regurgitate and transfer nectar to hive bees. Once in their own honey stomachs the hive bees regurgitate the nectar, repeatedly forming bubbles between their mandibles, speeding its digestion and concentration. These bubbles create a large surface area per volume and by this means the bees evaporate a portion of the nectar's water into the warm air of the hive. Hive bees form honey processing groups. These groups work in relay, with one bee subjecting the processed nectar to bubbling and then passing the refined liquid on to others. It can take as long as 20 minutes of continuous regurgitation, digestion and evaporation until the product reaches storage quality. The new honey is then placed in honeycomb cells, which are left uncapped. This honey still has a very high water content, up to 70%, depending on the concentration of nectar gathered. At this stage of its refinement the water content of the honey is high enough that ubiquitous
yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constit ...
spores can reproduce in it, a process which, if left unchecked, would rapidly consume the new honey's sugars. To combat this, bees use an ability rare among insects: the endogenous generation of heat. Bees are among the few insects that can create large amounts of body heat. They use this ability to produce a constant ambient temperature in their hives. Hive temperatures are usually around in the honey-storage areas. This temperature is regulated either by generating heat with their bodies or removing it through water evaporation. The evaporation removes water from the stored honey, drawing heat from the colony. The bees use their wings to govern hive cooling. Coordinated wing beating moves air across the wet honey, drawing out water and heat. Ventilation of the hive eventually expels both excess water and heat into the outside world. The process of evaporating continues until the honey reaches its final water content of between 15.5% to 18%. This concentrates the sugars far beyond the saturation point of water, which is to say there is far more sugar dissolved in what little water remains in honey than ever could be dissolved in an equivalent volume of water. Honey, even at hive temperatures, is therefore a supercooled solution of various sugars in water. These concentrations of sugar can only be achieved near room temperature by evaporation of a less concentrated solution, in this case nectar. For osmotic reasons such high concentrations of sugar are extremely unfavorable to microbiological reproduction and all fermentation is consequently halted. The bees then cap the cells of finished honey with wax. This seals them from contamination and prevents further evaporation. So long as its water concentration does not rise much above 18%, honey has an indefinite shelf life, both within the hive and after its removal by a
beekeeper A beekeeper is a person who keeps honey bees. Beekeepers are also called honey farmers, apiarists, or less commonly, apiculturists (both from the Latin '' apis'', bee; cf. apiary). The term beekeeper refers to a person who keeps honey bees i ...
.


By other insects

Honey bees are not the only eusocial insects to produce honey. Some wasp species, such as ''
Brachygastra lecheguana ''Brachygastra lecheguana'' (Latreille 1824), formerly known as ''Nectarina lecheguana'',Bequaert, J. Q. (1932). "The Nearctic social wasps of the subfamily polybiinae (Hymenoptera; Vespidae)". ''Entomologica Americana''. 13 (3): 87-150. is a spe ...
'' and '' Brachygastra mellifica,'' found in South and Central America, are known to feed on nectar and produce honey. Other wasps, such as '' Polistes versicolor'', also consume honey. In the middle of their lifecycles they alternate between feeding on protein-rich pollen and feeding on honey, which is a far
denser Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematically ...
source of food energy.


Human intervention

Human beings have semi-domesticated several species of honeybee by taking advantage of their swarming stage. Swarming is the means by which new colonies are established when there is no longer space for expansion in the colony's present hive. The old queen lays eggs that will develop into new queens and then leads as many as half the colony to a site for a new hive. Bees generally swarm before a suitable location for another hive has been discovered by scouts sent out for this purpose. Until such a location is found the swarm will simply conglomerate near the former hive, often from tree branches. These swarms are unusually docile and amenable to transport by humans. When provided with a suitable nesting site, such as a commercial Langstroth hive, the swarm will readily form a new colony in artificial surroundings. These semi-domesticated colonies are then looked after by humans practicing apiculture or meliponiculture. Captured bees are encouraged to forage, often in agricultural settings such as orchards, where pollinators are highly valued. The honey, pollen, wax and resins the bees produce are all harvested by humans for a variety of uses. The term "semi-domesticated" is preferred because all bee colonies, even those in very large agricultural apiculture operations, readily leave the protection of humans in swarms that can establish successful wild colonies. Much of the effort in commercial beekeeping is dedicated to persuading a hive that is ready to swarm to produce more honeycomb in its present location. This is usually done by adding more space to the colony with '' honey supers'', empty boxes placed on top of an existing colony. The bees can then usually be enticed to develop this empty space instead of dividing their colony through swarming.


Production


Collection

Honey is collected from wild bee colonies or from domesticated beehives. On average, a hive will produce about of honey per year. Wild bee nests are sometimes located by following a
honeyguide Honeyguides (family Indicatoridae) are near passerine birds in the order Piciformes. They are also known as indicator birds, or honey birds, although the latter term is also used more narrowly to refer to species of the genus ''Prodotiscus''. Th ...
bird. To safely collect honey from a hive, beekeepers typically pacify the bees using a bee smoker. The smoke triggers a feeding instinct (an attempt to save the resources of the hive from a possible fire), making them less aggressive, and obscures the pheromones the bees use to communicate. The honeycomb is removed from the hive and the honey may be extracted from it either by crushing or by using a
honey extractor A honey extractor is a mechanical device used in the extraction of honey from honeycombs. A honey extractor extracts the honey from the honey comb without destroying the comb. Extractors work by centrifugal force. A drum or container holds a ...
. The honey is then usually filtered to remove beeswax and other debris. Before the invention of removable frames, bee colonies were often sacrificed to conduct the harvest. The harvester would take all the available honey and replace the entire colony the next spring. Since the invention of removable frames, the principles of husbandry led most beekeepers to ensure that their bees have enough stores to survive the winter, either by leaving some honey in the beehive or by providing the colony with a honey substitute such as sugar water or crystalline sugar (often in the form of a "candyboard"). The amount of food necessary to survive the winter depends on the variety of bees and on the length and severity of local winters. Many animal species are attracted to wild or domestic sources of honey.


Preservation

Because of its composition and chemical properties, honey is suitable for long-term storage, and is easily assimilated even after long preservation. Honey, and objects immersed in honey, have been preserved for centuries. The key to preservation is limiting access to humidity. In its cured state, honey has a sufficiently high sugar content to inhibit fermentation. If exposed to moist air, its
hydrophilic A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press. In contrast, hydrophobes are n ...
properties pull moisture into the honey, eventually diluting it to the point that fermentation can begin. The long shelf life of honey is attributed to an
enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
found in the stomach of bees. The bees mix glucose oxidase with expelled nectar they previously consumed, creating two
byproduct A by-product or byproduct is a secondary product derived from a production process, manufacturing process or chemical reaction; it is not the primary product or service being produced. A by-product can be useful and marketable or it can be consid ...
s –
gluconic acid Gluconic acid is an organic compound with molecular formula C6H12O7 and condensed structural formula HOCH2(CHOH)4COOH. It is one of the 16 stereoisomers of 2,3,4,5,6-pentahydroxyhexanoic acid. In aqueous solution at neutral pH, gluconic acid ...
and
hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3 ...
, which are partially responsible for honey acidity and suppression of bacterial growth.


Adulteration

Honey is sometimes adulterated by the addition of other sugars, syrups, or compounds to change its flavor or viscosity, reduce cost, or increase the fructose content to stave off crystallization. Adulteration of honey has been practiced since ancient times, when honey was sometimes blended with plant syrups such as maple,
birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech- oak family Fagaceae. The genus ''Betula'' cont ...
, or sorghum and sold to customers as pure honey. Sometimes crystallized honey was mixed with flour or other fillers, hiding the adulteration from buyers until the honey was liquefied. In modern times the most common adulterant became clear, almost-flavorless corn syrup; the adulterated mixture can be very difficult to distinguish from pure honey. According to the Codex Alimentarius of the United Nations, any product labeled as "honey" or "pure honey" must be a wholly natural product, although labeling laws differ between countries. In the United States, according to the National Honey Board (NHB; supervised by the
United States Department of Agriculture The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of comme ...
), "honey stipulates a pure product that does not allow for the addition of any other substance... this includes, but is not limited to, water or other sweeteners". Isotope ratio mass spectrometry can be used to detect addition of corn syrup and
cane sugar Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and ref ...
by the carbon isotopic signature. Addition of sugars originating from corn or sugar cane ( C4 plants, unlike the plants used by bees, and also
sugar beet A sugar beet is a plant whose root contains a high concentration of sucrose and which is grown commercially for sugar production. In plant breeding, it is known as the Altissima cultivar group of the common beet ('' Beta vulgaris''). Together ...
, which are predominantly C3 plants) skews the isotopic ratio of sugars present in honey, but does not influence the isotopic ratio of proteins. In an unadulterated honey, the carbon isotopic ratios of sugars and proteins should match. Levels as low as 7% of addition can be detected.


Worldwide production

In 2020, global production of honey was 1.8million
tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000  kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...
s, led by China with 26% of the world total (table). Other major producers were
Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...
,
Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
,
Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the List of South American countries by area, second-largest ...
, and
Ukraine Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inva ...
.


Modern uses


Food

Over its history as a food, the main uses of honey are in cooking, baking, desserts, as a spread on bread, as an addition to various beverages such as tea, and as a sweetener in some commercial beverages. Due to its energy density, honey is an important food for virtually all hunter-gatherer cultures in warm climates, with the
Hadza people The Hadza, or Hadzabe (''Wahadzabe'' in Swahili), are a Tanzanian indigenous ethnic group mostly based in southwest Karatu District of Arusha Region. They live around Lake Eyasi in the central Rift Valley and in the neighboring Serengeti Plate ...
ranking honey as their favorite food. Honey hunters in Africa have a mutualistic relationship with certain species of
honeyguide Honeyguides (family Indicatoridae) are near passerine birds in the order Piciformes. They are also known as indicator birds, or honey birds, although the latter term is also used more narrowly to refer to species of the genus ''Prodotiscus''. Th ...
birds.


Fermentation

Possibly the world's oldest fermented beverage, dating from 9,000 years ago, mead ("honey wine") is the alcoholic product made by adding
yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constit ...
to honey-water must and fermenting it for weeks or months. The yeast ''
Saccharomyces cerevisiae ''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have b ...
'' is commonly used in modern mead production. Mead varieties include drinks called
metheglin Mead () is an alcoholic beverage made by fermenting honey mixed with water, and sometimes with added ingredients such as fruits, spices, grains, or hops. The alcoholic content ranges from about 3.5% ABV to more than 20%. The defining characte ...
(with spices or herbs),
melomel Mead () is an alcoholic beverage made by fermenting honey mixed with water, and sometimes with added ingredients such as fruits, spices, grains, or hops. The alcoholic content ranges from about 3.5% ABV to more than 20%. The defining character ...
(with fruit juices, such as grape, specifically called pyment),
hippocras Hippocras ( ca, Pimentes de clareya; lat, vīnum Hippocraticum), sometimes spelled hipocras or hypocras, is a drink made from wine mixed with sugar and spices, usually including cinnamon, and possibly heated. After steeping the spices in the ...
(with cinnamon), and sack mead (high concentration of honey), many of which have been developed as commercial products numbering in the hundreds in the United States. Honey is also used to make mead
beer Beer is one of the oldest and the most widely consumed type of alcoholic drink in the world, and the third most popular drink overall after water and tea. It is produced by the brewing and fermentation of starches, mainly derived from ce ...
, called "braggot".


Physical and chemical properties

The physical properties of honey vary, depending on water content, the type of flora used to produce it (pasturage), temperature, and the proportion of the specific sugars it contains. Fresh honey is a
supersaturated In physical chemistry, supersaturation occurs with a solution when the concentration of a solute exceeds the concentration specified by the value of solubility at equilibrium. Most commonly the term is applied to a solution of a solid in a li ...
liquid, containing more sugar than the water can typically dissolve at ambient temperatures. At room temperature, honey is a supercooled liquid, in which the glucose precipitates into solid granules. This forms a semisolid solution of precipitated glucose
crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macro ...
s in a solution of fructose and other ingredients. The
density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematicall ...
of honey typically ranges between 1.38 and 1.45 kg/L at 20 °C.


Phase transitions

The melting point of crystallized honey is between , depending on its composition. Below this temperature, honey can be either in a metastable state, meaning that it will not crystallize until a seed crystal is added, or, more often, it is in a "labile" state, being saturated with enough sugars to crystallize spontaneously. The rate of crystallization is affected by many factors, but the primary factor is the ratio of the main sugars: fructose to glucose. Honeys that are supersaturated with a very high percentage of glucose, such as brassica honey, crystallize almost immediately after harvesting, while honeys with a low percentage of glucose, such as chestnut or tupelo honey, do not crystallize. Some types of honey may produce few but very large crystals, while others produce many small crystals.Tomasik, Piotr (2004) ''Chemical and functional properties of food saccharides'', CRC Press, p. 74, Crystallization is also affected by water content, because a high percentage of water inhibits crystallization, as does a high dextrin content. Temperature also affects the rate of crystallization, with the fastest growth occurring between . Crystal nuclei (seeds) tend to form more readily if the honey is disturbed, by stirring, shaking, or agitating, rather than if left at rest. However, the nucleation of microscopic seed-crystals is greatest between . Therefore, larger but fewer crystals tend to form at higher temperatures, while smaller but more-numerous crystals usually form at lower temperatures. Below 5 °C, the honey will not crystallize, thus the original texture and flavor can be preserved indefinitely. Honey is a supercooled liquid when stored below its melting point, as is normal. At very low temperatures, honey does not freeze solid; rather its viscosity increases. Like most
viscous liquid In condensed matter physics and physical chemistry, the terms viscous liquid, supercooled liquid, and glassforming liquid are often used interchangeably to designate liquids that are at the same time highly viscous (see Viscosity of amorphous mat ...
s, the honey becomes thick and sluggish with decreasing temperature. At , honey may appear or even feel solid, but it continues to flow at very low rates. Honey has a glass transition between . Below this temperature, honey enters a
glass Glass is a non- crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenchin ...
y state and becomes an
amorphous solid In condensed matter physics and materials science, an amorphous solid (or non-crystalline solid, glassy solid) is a solid that lacks the long-range order that is characteristic of a crystal. Etymology The term comes from the Greek ''a'' (" ...
(noncrystalline).


Rheology

The
viscosity The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the int ...
of honey is affected greatly by both temperature and water content. The higher the water percentage, the more easily honey flows. Above its melting point, however, water has little effect on viscosity. Aside from water content, the composition of most types of honey also has little effect on viscosity. At , honey with 14% water content generally has a viscosity around 400  poise, while a honey containing 20% water has a viscosity around 20 poise. Viscosity increases very slowly with moderate cooling; a honey containing 16% water, at , has a viscosity around 2 poise, while at , the viscosity is around 70 poise. With further cooling, the increase in viscosity is more rapid, reaching 600 poise at around . However, while honey is viscous, it has low
surface tension Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) t ...
of 50–60 mJ/m2, making its wettability similar to water, glycerin, or most other liquids. The high viscosity and wettability of honey cause stickiness, which is a time-dependent process in supercooled liquids between the glass-transition temperature (Tg) and the crystalline-melting temperature. Most types of honey are Newtonian liquids, but a few types have non-Newtonian viscous properties. Honeys from heather or manuka display thixotropic properties. These types of honey enter a gel-like state when motionless, but liquefy when stirred.


Electrical and optical properties

Because honey contains electrolytes, in the form of acids and minerals, it exhibits varying degrees of electrical conductivity. Measurements of the electrical conductivity are used to determine the quality of honey in terms of
ash Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non-gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...
content. The effect honey has on light is useful for determining the type and quality. Variations in its water content alter its
refractive index In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, ...
. Water content can easily be measured with a refractometer. Typically, the refractive index for honey ranges from 1.504 at 13% water content to 1.474 at 25%. Honey also has an effect on polarized light, in that it rotates the polarization plane. The fructose gives a negative rotation, while the glucose gives a positive one. The overall rotation can be used to measure the ratio of the mixture. Root, p. 348 Honey may vary in color between pale yellow and dark brown, but other bright colors may occasionally be found, depending on the source of the sugar harvested by the bees. Bee colonies that forage on Kudzu ( ''Pueraria montana'' var. ''lobata'') flowers, for example, produce honey that varies in color from red to purple.


Hygroscopy and fermentation

Honey has the ability to absorb moisture directly from the air, a phenomenon called hygroscopy. The amount of water the honey absorbs is dependent on the relative humidity of the air. Because honey contains yeast, this hygroscopic nature requires that honey be stored in sealed containers to prevent fermentation, which usually begins if the honey's water content rises much above 25%. Honey tends to absorb more water in this manner than the individual sugars allow on their own, which may be due to other ingredients it contains. Fermentation of honey usually occurs after crystallization, because without the glucose, the liquid portion of the honey primarily consists of a concentrated mixture of fructose, acids, and water, providing the yeast with enough of an increase in the water percentage for growth. Honey that is to be stored at room temperature for long periods of time is often pasteurized, to kill any yeast, by heating it above .


Thermal characteristics

Like all sugar compounds, honey caramelizes if heated sufficiently, becoming darker in color, and eventually burns. However, honey contains fructose, which caramelizes at lower temperatures than glucose. The temperature at which caramelization begins varies, depending on the composition, but is typically between . Honey also contains acids, which act as
catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
s for caramelization. The specific types of acids and their amounts play a primary role in determining the exact temperature. Of these acids, the amino acids, which occur in very small amounts, play an important role in the darkening of honey. The amino acids form darkened compounds called melanoidins, during a
Maillard reaction The Maillard reaction ( ; ) is a chemical reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. Seared steaks, fried dumplings, cookies and other kinds of biscuits, breads, toasted marshmallows, and m ...
. The Maillard reaction occurs slowly at room temperature, taking from a few to several months to show visible darkening, but speeds up dramatically with increasing temperatures. However, the reaction can also be slowed by storing the honey at colder temperatures. Unlike many other liquids, honey has very poor
thermal conductivity The thermal conductivity of a material is a measure of its ability to conduct heat. It is commonly denoted by k, \lambda, or \kappa. Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal ...
of 0.5 W/(m⋅K) at 13% water content (compared to 401 W/(m⋅K) of
copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pink ...
), taking a long time to reach
thermal equilibrium Two physical systems are in thermal equilibrium if there is no net flow of thermal energy between them when they are connected by a path permeable to heat. Thermal equilibrium obeys the zeroth law of thermodynamics. A system is said to be in ...
. Due to its high kinematic viscosity honey does not transfer heat through momentum diffusion (
convection Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the c ...
) but rather through thermal diffusion (more like a solid), so melting crystallized honey can easily result in localized caramelization if the heat source is too hot or not evenly distributed. However, honey takes substantially longer to liquefy when just above the melting point than at elevated temperatures. Melting 20 kg of crystallized honey at can take up to 24 hours, while 50 kg may take twice as long. These times can be cut nearly in half by heating at ; however, many of the minor substances in honey can be affected greatly by heating, changing the flavor, aroma, or other properties, so heating is usually done at the lowest temperature and for the shortest time possible.


Acid content and flavor effects

The average pH of honey is 3.9, but can range from 3.4 to 6.1. Honey contains many kinds of acids, both
organic Organic may refer to: * Organic, of or relating to an organism, a living entity * Organic, of or relating to an anatomical organ Chemistry * Organic matter, matter that has come from a once-living organism, is capable of decay or is the product ...
and amino. However, the different types and their amounts vary considerably, depending on the type of honey. These acids may be
aromatic In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to satur ...
or
aliphatic In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated, like hexane ...
(nonaromatic). The aliphatic acids contribute greatly to the flavor of honey by interacting with the flavors of other ingredients. Organic acids comprise most of the acids in honey, accounting for 0.17–1.17% of the mixture, with
gluconic acid Gluconic acid is an organic compound with molecular formula C6H12O7 and condensed structural formula HOCH2(CHOH)4COOH. It is one of the 16 stereoisomers of 2,3,4,5,6-pentahydroxyhexanoic acid. In aqueous solution at neutral pH, gluconic acid ...
formed by the actions of glucose oxidase as the most prevalent. Minor amounts of other organic acids are present, consisting of formic, acetic, butyric, citric, lactic, malic, pyroglutamic, propionic, valeric, capronic, palmitic, and succinic, among many others.


Volatile organic compounds

Individual honeys from different plant sources contain over 100 volatile organic compounds (VOCs), which play a primary role in determining honey flavors and aromas. VOCs are carbon-based compounds that readily vaporize into the air, providing aroma, including the scents of flowers, essential oils, or ripening fruit. The typical chemical families of VOCs found in honey include
hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...
s,
aldehyde In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl gro ...
s, alcohols, ketones,
ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...
s, acids,
benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms ...
s, furans, pyrans,
norisoprenoid Terpenes () are a class of natural products consisting of compounds with the formula (C5H8)n for n > 1. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predominantly by plants, particularly conifers. Terpenes ar ...
s, and
terpene Terpenes () are a class of natural products consisting of compounds with the formula (C5H8)n for n > 1. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predominantly by plants, particularly conifers. Terpenes ...
s, among many others and their derivatives. The specific VOCs and their amounts vary considerably between different types of honey obtained by bees foraging on different plant sources. By example, when comparing the mixture of VOCs in different honeys in one review,
longan ''Dimocarpus longan'', commonly known as the longan () and dragon's eye, is a tropical tree species that produces edible fruit. It is one of the better-known tropical members of the soapberry family Sapindaceae, to which the lychee and rambu ...
honey had a higher amount of volatiles (48 VOCs), while
sunflower The common sunflower (''Helianthus annuus'') is a large annual forb of the genus ''Helianthus'' grown as a crop for its edible oily seeds. Apart from cooking oil production, it is also used as livestock forage (as a meal or a silage plant), ...
honey had the lowest number of volatiles (8 VOCs). VOCs are primarily introduced into the honey from the nectar, where they are excreted by the flowers imparting individual scents. The specific types and concentrations of certain VOCs can be used to determine the type of flora used to produce monofloral honeys. The specific geography, soil composition and acidity used to grow the flora also have an effect on honey aroma properties, such as a "fruity" or "grassy" aroma from longan honey, or a "waxy" aroma from sunflower honey. Dominant VOCs in one study were
linalool Linalool () refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch of ...
oxide, trans-linalool oxide, 2- phenylacetaldehyde, benzyl
ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a ...
, isophorone, and methyl nonanoate. VOCs can also be introduced from the bodies of the bees, be produced by the enzymatic actions of digestion, or from chemical reactions that occur between different substances within the honey during storage, and therefore may change, increase, or decrease over long periods of time. VOCs may be produced, altered, or greatly affected by temperature and processing. Some VOCs are heat labile, and are destroyed at elevated temperatures, while others can be created during non-enzymatic reactions, such as the
Maillard reaction The Maillard reaction ( ; ) is a chemical reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. Seared steaks, fried dumplings, cookies and other kinds of biscuits, breads, toasted marshmallows, and m ...
. VOCs are responsible for nearly all of the aroma produced by a honey, which may be described as "sweet", "flowery", "citrus", "almond" or "rancid", among other terms. In addition, VOCs play a large role in determining the specific flavor of the honey, both through the aromas and flavor. VOCs from honeys in different geographic regions can be used as floral markers of those regions, and as markers of the bees that foraged the nectars.


Classification

Honey is classified by its floral source, and divisions are made according to the packaging and processing used. Regional honeys are also identified. In the US, honey is also graded on its color and optical density by
USDA The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of comme ...
standards, graded on the Pfund scale, which ranges from 0 for "water white" honey to more than 114 for "dark amber" honey.


Floral source

Generally, honey is classified by the floral source of the nectar from which it was made. Honeys can be from specific types of flower nectars or can be blended after collection. The pollen in honey is traceable to floral source and therefore region of origin. The rheological and melissopalynological properties of honey can be used to identify the major plant nectar source used in its production.


Blended

Most commercially available honey is a blend of two or more honeys differing in floral source, color, flavor, density, or geographic origin.


Polyfloral

Polyfloral honey, also known as wildflower honey, is derived from the nectar of many types of flowers. The taste may vary from year to year, and the aroma and the flavor can be more or less intense, depending on which flowers are blooming.


Monofloral

Monofloral honey is made primarily from the nectar of one type of flower. Monofloral honeys have distinctive flavors and colors because of differences between their principal nectar sources.The Colours Of Honey
. Mieliditalia.it. Retrieved on 6 February 2011.
To produce monofloral honey, beekeepers keep beehives in an area where the bees have access, as far as possible, to only one type of flower. In practice a small proportion of any monofloral honey will be from other flower types. Typical examples of North American monofloral honeys are
clover Clover or trefoil are common names for plants of the genus ''Trifolium'' (from Latin ''tres'' 'three' + ''folium'' 'leaf'), consisting of about 300 species of flowering plants in the legume or pea family Fabaceae originating in Europe. The genus ...
,
orange blossom Orange Blossom is a French band that plays a mix of electronic and world music. The band was formed in Nantes in 1993 with Pierre-Jean Chabot (known as ''PJ Chabot'') on violin and Jean-Christophe Waechter (known as ''Jay C.'') on percussions ...
, sage, tupelo,
buckwheat Buckwheat (''Fagopyrum esculentum''), or common buckwheat, is a flowering plant in the knotweed family Polygonaceae cultivated for its grain-like seeds and as a cover crop. The name "buckwheat" is used for several other species, such as ''Fagop ...
, fireweed, mesquite,
sourwood ''Oxydendrum arboreum'', the sourwood or sorrel tree, is the sole species in the genus ''Oxydendrum'', in the family Ericaceae. It is native to eastern North America, from southern Pennsylvania south to northwest Florida and west to souther ...
, cherry, and blueberry. Some typical European examples include
thyme Thyme () is the herb (dried aerial parts) of some members of the genus ''Thymus'' of aromatic perennial evergreen herbs in the mint family Lamiaceae. Thymes are relatives of the oregano genus '' Origanum'', with both plants being mostly indigen ...
,
thistle Thistle is the common name of a group of flowering plants characterised by leaves with sharp prickles on the margins, mostly in the family Asteraceae. Prickles can also occur all over the planton the stem and on the flat parts of the leaves ...
, heather, acacia, dandelion,
sunflower The common sunflower (''Helianthus annuus'') is a large annual forb of the genus ''Helianthus'' grown as a crop for its edible oily seeds. Apart from cooking oil production, it is also used as livestock forage (as a meal or a silage plant), ...
, lavender,
honeysuckle Honeysuckles are arching shrubs or twining vines in the genus ''Lonicera'' () of the family Caprifoliaceae, native to northern latitudes in North America and Eurasia. Approximately 180 species of honeysuckle have been identified in both con ...
, and varieties from lime and chestnut trees. In North Africa (e.g. Egypt), examples include clover,
cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor pe ...
, and
citrus ''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is native to ...
(mainly orange blossoms). The unique flora of Australia yields a number of distinctive honeys, with some of the most popular being yellow box, blue gum, ironbark, bush mallee, Tasmanian leatherwood, and macadamia.


Honeydew honey

Instead of taking nectar, bees can take honeydew, the sweet secretions of aphids or other plant-sap-sucking insects. Honeydew honey is very dark brown, with a rich fragrance of stewed fruit or fig jam, and is not as sweet as nectar honeys. Germany's
Black Forest The Black Forest (german: Schwarzwald ) is a large forested mountain range in the state of Baden-Württemberg in southwest Germany, bounded by the Rhine Valley to the west and south and close to the borders with France and Switzerland. It is ...
is a well-known source of honeydew-based honeys, as are some regions in Bulgaria, Tara in Serbia, and Northern California in the United States. In Greece, pine honey, a type of honeydew honey, constitutes 60–65% of honey production. Honeydew honey is popular in some areas, but in other areas, beekeepers have difficulty selling honeydew honey, due to its stronger flavor. The production of honeydew honey has some complications and dangers. This honey has a much larger proportion of indigestibles than light floral honeys, thus causing dysentery to the bees, resulting in the death of colonies in areas with cold winters. Good beekeeping management requires the removal of honeydew prior to winter in colder areas. Bees collecting this resource also have to be fed protein supplements, as honeydew lacks the protein-rich pollen accompaniment gathered from flowers. Honeydew honey is sometimes called "myelate".


Classification by packaging and processing

Generally, honey is bottled in its familiar liquid form, but it is sold in other forms, and can be subjected to a variety of processing methods. * Crystallized honey occurs when some of the glucose content has spontaneously crystallized from solution as the monohydrate. It is also called "granulated honey" or "candied honey". Honey that has crystallized (or is commercially purchased crystallized) can be returned to a liquid state by warming. * Pasteurized honey has been heated in a pasteurization process which requires temperatures of or higher. Pasteurization destroys yeast cells. It also liquefies any microcrystals in the honey, which delays the onset of visible crystallization. However, excessive heat exposure also results in product deterioration, as it increases the level of
hydroxymethylfurfural Hydroxymethylfurfural (HMF), also 5-(hydroxymethyl)furfural, is an organic compound formed by the dehydration of reducing sugars. It is a white low-melting solid (although commercial samples are often yellow) which is highly soluble in both water ...
(HMF) and reduces enzyme (e.g. diastase) activity. Heat also darkens the honey, and affects taste and fragrance. * Raw honey is as it exists in the beehive or as obtained by extraction, settling, or straining, without adding heat (although some honey that has been "minimally processed" is often labeled as raw honey). Raw honey contains some pollen and may contain small particles of wax. * Strained honey has been passed through a mesh material to remove particulate material (pieces of wax, propolis, other defects) without removing pollen, minerals, or enzymes. * Filtered honey of any type has been filtered to the extent that all or most of the fine particles, pollen grains, air bubbles, or other materials normally found in suspension, have been removed. The process typically heats honey to to more easily pass through the filter. Filtered honey is very clear and will not crystallize as quickly, making it preferred by supermarkets. The most common method involves the addition of diatomaceous earth to honey that is heated to and passed through filter paper or canvas until a filter cake of diatomaceous earth builds up on the filter. * Ultrasonicated honey has been processed by
ultrasonication image:Sonicator.jpg, A sonicator at the Weizmann Institute of Science during sonicationSonication is the act of applying sound energy to agitate particles in a sample, for various purposes such as the extraction of multiple compounds from plants, m ...
, a nonthermal processing alternative for honey. When honey is exposed to ultrasonication, most of the yeast cells are destroyed. Those cells that survive sonication generally lose their ability to grow, which reduces the rate of honey fermentation substantially. Ultrasonication also eliminates existing crystals and inhibits further crystallization in honey. Ultrasonically aided liquefaction can work at substantially lower temperatures around and can reduce liquefaction time to less than 30 seconds. * Creamed honey, also called whipped honey, spun honey, churned honey, honey fondant, and, in the UK, set honey, has been processed to control crystallization. Creamed honey contains a large number of small crystals, which prevent the formation of larger crystals that can occur in unprocessed honey. The processing also produces a honey with a smooth, spreadable consistency. * Dried honey has the moisture extracted from liquid honey to create completely solid, nonsticky granules. This process may or may not include the use of drying and anticaking agents. Dried honey is used in baked goods, and to garnish desserts. *
Comb honey Comb honey is honey intended for consumption by humans, which is still contained within its original hexagonal-shaped beeswax cells, called honeycomb. It has received no processing, filtering, or manipulation, and is in the state that honey bees ha ...
is still in the honeybees' wax comb. It is traditionally collected using standard wooden frames in honey supers. The frames are collected and the comb is cut out in chunks before packaging. As an alternative to this labor-intensive method, plastic rings or cartridges can be used that do not require manual cutting of the comb, and speed packaging. Comb honey harvested in the traditional manner is also referred to as "cut-comb honey". * Chunk honey is packed in wide-mouthed containers; it consists of one or more pieces of comb honey immersed in extracted liquid honey. * Honey decoctions are made from honey or honey byproducts which have been dissolved in water, then reduced (usually by means of boiling). Other ingredients may then be added. (For example, abbamele has added citrus.) The resulting product may be similar to molasses. * Baker's honey is outside the normal specification for honey, due to a "foreign" taste or odor, or because it has begun to ferment or has been overheated. It is generally used as an ingredient in food processing. Additional requirements exist for labeling baker's honey, including that it may not be sold labeled simply as "honey".


Grading

Countries have differing standards for grading honey. In the US, honey grading is performed voluntarily based upon USDA standards. USDA offers inspection and grading "as on-line (in-plant) or lot inspection...upon application, on a fee-for-service basis." Honey is graded based upon a number of factors, including water content, flavor and aroma, absence of defects, and clarity. Honey is also classified by color, though it is not a factor in the grading scale. The honey grade scale is: India certifies honey grades based on additional factors, such as the Fiehe's test, and other empirical measurements.


Indicators of quality

High-quality honey can be distinguished by fragrance, taste, and consistency. Ripe, freshly collected, high-quality honey at should flow from a knife in a straight stream, without breaking into separate drops. After falling down, the honey should form a bead. The honey, when poured, should form small, temporary layers that disappear fairly quickly, indicating high viscosity. If not, it indicates honey with excessive water content of over 20%, not suitable for long-term preservation. In jars, fresh honey should appear as a pure, consistent fluid, and should not set in layers. Within a few weeks to a few months of extraction, many varieties of honey crystallize into a cream-colored solid. Some varieties of honey, including tupelo, acacia, and sage, crystallize less regularly. Honey may be heated during bottling at temperatures of to delay or inhibit crystallization. Overheating is indicated by change in enzyme levels, for instance, diastase activity, which can be determined with the Schade or the
Phadebas Phadebas is a synthetic biochemical substrate used for both qualitative and quantitative assessment of the α-amylase enzyme. Its active component is DSM-P, microspheres in which a blue dye has been chemically bound. When the substrate is dige ...
methods. A fluffy film on the surface of the honey (like a white foam), or marble-colored or white-spotted crystallization on a container's sides, is formed by air bubbles trapped during the bottling process. A 2008 Italian study determined that nuclear magnetic resonance spectroscopy can be used to distinguish between different honey types, and can be used to pinpoint the area where it was produced. Researchers were able to identify differences in acacia and polyfloral honeys by the differing proportions of fructose and sucrose, as well as differing levels of aromatic
amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha ...
s phenylalanine and
tyrosine -Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the G ...
. This ability allows greater ease of selecting compatible stocks.


Nutrition

One hundred grams of honey provides about of energy with no significant amounts of essential nutrients. Composed of 17% water and 82%
carbohydrate In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may o ...
s, honey has low content of fat, dietary fiber, and
protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
.


Sugar profile

A mixture of sugars and other carbohydrates, honey is mainly fructose (about 38%) and
glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...
(about 32%), with remaining sugars including maltose, sucrose, and other complex carbohydrates. Its
glycemic index The glycemic (glycaemic) index (GI; ) is a number from 0 to 100 assigned to a food, with pure glucose arbitrarily given the value of 100, which represents the relative rise in the blood glucose level two hours after consuming that food. The GI of ...
ranges from 31 to 78, depending on the variety. The specific composition, color, aroma, and flavor of any batch of honey depend on the flowers foraged by bees that produced the honey. One 1980 study found that mixed floral honey from several United States regions typically contains the following: * Fructose: 38.2% * Glucose: 31.3% * Maltose: 7.1% * Sucrose: 1.3% * Water: 17.2% * Higher sugars: 1.5% * Ash: 0.2% * Other/undetermined: 3.2% This means that 55% of the combined fructose and glucose content was fructose and 45% was glucose, which enables comparison with the essentially identical result (average of 56% and 44%) in the study described below: A 2013
NMR spectroscopy Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique to observe local magnetic fields around atomic nuclei. The sample is placed in a magnetic fi ...
study of 20 different honeys from Germany found that their sugar contents comprised: * Fructose: 28% to 41% * Glucose: 22% to 35% The average ratio was 56% fructose to 44% glucose, but the ratios in the individual honeys ranged from a high of 64% fructose and 36% glucose (one type of flower honey; table 3 in reference) to a low of 50% fructose and 50% glucose (a different floral source). This NMR method was not able to quantify maltose, galactose, and the other minor sugars as compared to fructose and glucose.


Medical use and research


Wounds and burns

Honey is a folk treatment for burns and other skin injuries. Preliminary evidence suggests that it aids in the healing of partial thickness burns 4–5 days faster than other dressings, and moderate evidence suggests that post-operative infections treated with honey heal faster and with fewer adverse events than with antiseptic and gauze. The evidence for the use of honey in various other wound treatments is of low quality, and firm conclusions cannot be drawn. Evidence does not support the use of honey-based products for the treatment of venous stasis ulcers or ingrown toenail. Several medical-grade honey products have been approved by the FDA for use in treating minor wounds and burns.


Antibiotic

Honey has long been used as a
topical antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...
by practitioners of
traditional A tradition is a belief or behavior (folk custom) passed down within a group or society with symbolic meaning or special significance with origins in the past. A component of cultural expressions and folklore, common examples include holidays or ...
and herbal medicine. Honey's antibacterial effects were first demonstrated by the Dutch scientist Bernardus Adrianus van Ketel in 1892. Since then, numerous studies have shown that honey has broad-spectrum antibacterial activity against gram-positive and
gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...
bacteria, although potency varies widely between different honeys. Due to the proliferation of antibiotic-resistant bacteria in the last few decades, there has been renewed interest in researching the antibacterial properties of honey. Components of honey under preliminary research for potential antibiotic use include methylglyoxal,
hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3 ...
, and royalisin (also called defensin-1).


Cough

For chronic and acute coughs, a
Cochrane review Cochrane (previously known as the Cochrane Collaboration) is a British international charitable organisation formed to organise medical research findings to facilitate evidence-based choices about health interventions involving health professi ...
found no strong evidence for or against the use of honey. For treating children, the systematic review concluded with moderate to low evidence that honey helps more than no treatment,
diphenhydramine Diphenhydramine (DPH) is an antihistamine and sedative mainly used to treat allergies, insomnia, and symptoms of the common cold. It is also less commonly used for tremor in parkinsonism, and nausea. It is taken by mouth, injected into ...
, and
placebo A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures. In general ...
at giving relief from coughing. Honey does not appear to work better than
dextromethorphan Dextromethorphan (DXM) is a medication most often used as a cough suppressant in over-the-counter cold and cough medicines. It is sold in syrup, tablet, spray, and lozenge forms. In 2022, the FDA approved a formulation of it combined with b ...
at relieving coughing in children. Other reviews have also supported the use of honey for treating children. The UK Medicines and Healthcare products Regulatory Agency recommends avoiding giving
over-the-counter Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs, which may be supplied only to consumers possessing a valid prescr ...
cough and common cold medication to children under six, and suggests "a homemade remedy containing honey and lemon is likely to be just as useful and safer to take", but warns that honey should not be given to babies because of the risk of infant botulism. The World Health Organization recommends honey as a treatment for coughs and sore throats, including for children, stating that no reason exists to believe it is less effective than a commercial remedy.


Other

The use of honey has been recommended as a temporary intervention for known or suspected
button cell A button cell, watch battery, or coin battery is a small single-cell battery shaped as a squat cylinder typically in diameter and high — resembling a button. Stainless steel usually forms the bottom body and positive terminal of the cell; in ...
battery ingestions to reduce the risk and severity of injury to the
esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...
caused by the battery prior to its removal. There is no evidence that honey is beneficial for treating
cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
, although honey may be useful for controlling side effects of
radiation therapy Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Rad ...
or
chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemother ...
used to treat cancer. Consumption is sometimes advocated as a treatment for seasonal allergies due to pollen, but scientific evidence to support the claim is inconclusive. Honey is generally considered ineffective for the treatment of allergic conjunctivitis. The majority of calories in honey are from fructose. When consumed in addition to a normal diet, fructose causes significant weight gain, but when fructose was substituted for other carbohydrates of equal energy value there was no effect on body weight. Honey has a mild laxative effect which has been noted as being helpful in alleviating constipation and bloating.


Health hazards

Honey is generally safe when taken in typical food amounts, but it may have various, potential
adverse effect An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a " side effect", when judged to be secondary to a main or therapeutic effect. The term compl ...
s or
interactions Interaction is action that occurs between two or more objects, with broad use in philosophy and the sciences. It may refer to: Science * Interaction hypothesis, a theory of second language acquisition * Interaction (statistics) * Interactions ...
in combination with excessive consumption, existing
disease A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
conditions, or drugs. Included among these are mild reactions to high intake, such as
anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...
,
insomnia Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, ...
, or hyperactivity in about 10% of children, according to one study. No symptoms of anxiety, insomnia, or hyperactivity were detected with honey consumption compared to
placebo A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures. In general ...
, according to another study. Honey consumption may interact adversely with existing allergies, high
blood sugar Glycaemia, also known as blood sugar level, blood sugar concentration, or blood glucose level is the measure of glucose concentrated in the blood of humans or other animals. Approximately 4 grams of glucose, a simple sugar, is present in the b ...
levels (as in
diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...
), or anticoagulants used to control bleeding, among other clinical conditions. People who have a weakened immune system may be at risk of bacterial or fungal infection from eating honey.


Botulism

Infants can develop botulism after consuming honey contaminated with '' Clostridium botulinum'' endospores. Infantile botulism shows geographical variation. In the UK, only six cases were reported between 1976 and 2006, yet the US has much higher rates: 1.9 per 100,000 live births, 47.2% of which are in California.Botulism in the United States, 1899–1996
Handbook for Epidemiologists, Clinicians, and Laboratory Workers, Atlanta, GA. Centers for Disease Control and Prevention (1998)
While the risk honey poses to infant health is small, taking the risk is not recommended until after one year of age, and then giving honey is considered safe.


Toxic honey

Mad honey intoxication is a result of eating honey containing grayanotoxins. Honey produced from flowers of rhododendrons, mountain laurels,
sheep laurel ''Kalmia angustifolia'' is a flowering shrub in the family Ericaceae, commonly known as sheep laurel. It is distributed in eastern North America from Ontario and Quebec south to Virginia. It grows commonly in dry habitats in the boreal forest, a ...
, and azaleas may cause honey intoxication. Symptoms include dizziness, weakness, excessive perspiration, nausea, and vomiting. Less commonly, low blood pressure, shock, heart rhythm irregularities, and convulsions may occur, with rare cases resulting in death. Honey intoxication is more likely when using "natural" unprocessed honey and honey from farmers who may have a small number of hives. Commercial processing, with pooling of honey from numerous sources, is thought to dilute any toxins.
in the ''Foodborne Pathogenic Microorganisms and Natural Toxins Handbook'', FDA Center for Food Safety and Applied Nutrition.
Toxic honey may also result when bees are proximate to Tutu (plant), tutu bushes (''Coriaria arborea'') and the vine hopper insect ('' Scolypopa australis''). Both are found throughout New Zealand. Bees gather honeydew produced by the vine hopper insects feeding on the tutu plant. This introduces the poison tutin into honey. Only a few areas in New Zealand (the Coromandel Peninsula, Eastern Bay of Plenty and the Marlborough Sounds) frequently produce toxic honey. Symptoms of tutin poisoning include vomiting, delirium, giddiness, increased excitability, stupor, coma, and violent convulsions. To reduce the risk of tutin poisoning, humans should not eat honey taken from feral hives in the risk areas of New Zealand. Since December 2001, New Zealand beekeepers have been required to reduce the risk of producing toxic honey by closely monitoring tutu, vine hopper, and foraging conditions within of their apiary. Intoxication is rarely dangerous.


Folk medicine

In myths and folk medicine, honey was used both orally and topically to treat various ailments including gastric disturbances, ulcers,
skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...
wounds, and skin burns by ancient Greeks and Egyptians, and in
Ayurveda Ayurveda () is an alternative medicine system with historical roots in the Indian subcontinent. The theory and practice of Ayurveda is pseudoscientific. Ayurveda is heavily practiced in India and Nepal, where around 80% of the population rep ...
and traditional Chinese medicine.


History

Honey collection is an ancient activity, long preceding the honey bee's domestication; this traditional practice is known as honey hunting. A Mesolithic rock painting in a cave in Valencia, Spain, dating back at least 8,000 years, depicts two honey foragers collecting honey and honeycomb from a wild bees' nest. The figures are depicted carrying baskets or gourds, and using a
ladder A ladder is a vertical or inclined set of rungs or steps used for climbing or descending. There are two types: rigid ladders that are self-supporting or that may be leaned against a vertical surface such as a wall, and rollable ladders, such ...
or series of ropes to reach the nest.Crane, Eva (1983) ''The Archaeology of Beekeeping'', Cornell University Press, Humans followed the
greater honeyguide The greater honeyguide (''Indicator indicator'') is a bird in the family Indicatoridae, paleotropical near passerine birds related to the woodpeckers. Its English and scientific names refer to its habit of guiding people to bee colonies. Cla ...
bird to wild beehives; this behavior may have evolved with early hominids. The oldest known honey remains were found in Georgia during the construction of the Baku–Tbilisi–Ceyhan pipeline: archaeologists found honey remains on the inner surface of clay vessels unearthed in an ancient tomb, dating back between 4,700 and 5,500 years. In ancient Georgia, several types of honey were buried with a person for journeys into the afterlife, including linden, berry, and meadow-flower varieties. The first written records of beekeeping are from ancient Egypt, where honey was used to sweeten cakes, biscuits, and other foods and as a base for unguents in Egyptian hieroglyphs. The dead were often buried in or with honey in Egypt,
Mesopotamia Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the ...
and other regions. Bees were kept at temples to produce honey for temple offerings, mummification and other uses. In
ancient Greece Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cu ...
, honey was produced from the Archaic to the
Hellenistic period In Classical antiquity, the Hellenistic period covers the time in Mediterranean history after Classical Greece, between the death of Alexander the Great in 323 BC and the emergence of the Roman Empire, as signified by the Battle of Actium in ...
s. In 594 BC, beekeeping around
Athens Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital and largest city of Greece. With a population close to four million, it is also the seventh largest city in the European Union. Athens dominates a ...
was so widespread that
Solon Solon ( grc-gre, Σόλων;  BC) was an Athenian statesman, constitutional lawmaker and poet. He is remembered particularly for his efforts to legislate against political, economic and moral decline in Archaic Athens.Aristotle ''Politic ...
passed a law about it: "He who sets up hives of bees must put them away from those already installed by another". Greek archaeological excavations of pottery located ancient hives. According to Columella, Greek beekeepers of the Hellenistic period did not hesitate to move their hives over rather long distances to maximize production, taking advantage of the different vegetative cycles in different regions. The spiritual and supposed therapeutic use of honey in
ancient India According to consensus in modern genetics, anatomically modern humans first arrived on the Indian subcontinent from Africa between 73,000 and 55,000 years ago. Quote: "Y-Chromosome and Mt-DNA data support the colonization of South Asia by ...
was documented in both the
Vedas upright=1.2, The Vedas are ancient Sanskrit texts of Hinduism. Above: A page from the '' Atharvaveda''. The Vedas (, , ) are a large body of religious texts originating in ancient India. Composed in Vedic Sanskrit, the texts constitute th ...
and the
Ayurveda Ayurveda () is an alternative medicine system with historical roots in the Indian subcontinent. The theory and practice of Ayurveda is pseudoscientific. Ayurveda is heavily practiced in India and Nepal, where around 80% of the population rep ...
texts. Biblical references include the description of Israel as the "land of milk and honey". The Book of Proverbs says, "Eat honey, my son, for it is good" (Prov. 24:13), but also, "It is not good to eat much honey" (Prov. 25:27). Early Christians used honey as a symbol of spiritual perfection in christening ceremonies. St.
John the Baptist John the Baptist or , , or , ;Wetterau, Bruce. ''World history''. New York: Henry Holt and Company. 1994. syc, ܝܘܿܚܲܢܵܢ ܡܲܥܡܕ݂ܵܢܵܐ, Yoḥanān Maʿmḏānā; he, יוחנן המטביל, Yohanān HaMatbil; la, Ioannes Bapti ...
was said to have sustained himself on a diet of honey and locusts.


Religious significance

In ancient Greek religion, the food of Zeus and the twelve
Gods of Olympus upright=1.8, Fragment of a relief (1st century BC1st century AD) depicting the twelve Olympians carrying their attributes in procession; from left to right: Hestia (scepter), Hermes (winged cap and staff), Aphrodite (veiled), Ares (helmet and ...
was honey in the form of nectar and ambrosia. In
Hinduism Hinduism () is an Indian religion or '' dharma'', a religious and universal order or way of life by which followers abide. As a religion, it is the world's third-largest, with over 1.2–1.35 billion followers, or 15–16% of the global p ...
, honey ('' Madhu'') is one of the five elixirs of life ('' Panchamrita''). In temples, honey is poured over the deities in a ritual called ''Madhu abhisheka''. The ''Vedas'' and other ancient literature mention the use of honey as a great medicinal and health food.A Meaningful Story of Buddha, Elephant and Monkey
by Marguerite Theophil, United Press International, 16 November 2006, accessed 9 August 2008
In Jewish tradition, honey is a symbol for the new year, '' Rosh Hashanah''. At the traditional meal for that holiday, apple slices are dipped in honey and eaten to bring a sweet new year. Some ''Rosh Hashanah'' greetings show honey and an apple, symbolizing the feast. In some congregations, small straws of honey are given out to usher in the new year. The
Hebrew Bible The Hebrew Bible or Tanakh (;"Tanach"
'' Book of Judges The Book of Judges (, ') is the seventh book of the Hebrew Bible and the Christian Old Testament. In the narrative of the Hebrew Bible, it covers the time between the conquest described in the Book of Joshua and the establishment of a kingdo ...
, Samson found a swarm of bees and honey in the carcass of a lion (14:8). Biblical law covered offerings made in the temple to God. The
Book of Leviticus The book of Leviticus (, from grc, Λευιτικόν, ; he, וַיִּקְרָא, , "And He called") is the third book of the Torah (the Pentateuch) and of the Old Testament, also known as the Third Book of Moses. Scholars generally agree ...
says that "Every grain offering you bring to the Lord must be made without yeast, for you are not to burn any yeast or honey in a food offering presented to the Lord" (2:11). In the
Books of Samuel The Book of Samuel (, ''Sefer Shmuel'') is a book in the Hebrew Bible, found as two books (1–2 Samuel) in the Old Testament. The book is part of the narrative history of Ancient Israel called the Deuteronomistic history, a series of books ( Jo ...
,
Jonathan Jonathan may refer to: *Jonathan (name), a masculine given name Media * ''Jonathan'' (1970 film), a German film directed by Hans W. Geißendörfer * ''Jonathan'' (2016 film), a German film directed by Piotr J. Lewandowski * ''Jonathan'' (2018 ...
is forced into a confrontation with his father King Saul after eating honey in violation of a rash oath Saul has made. Proverbs 16:24 in the JPS Tanakh 1917 version says "Pleasant words are as a honeycomb, Sweet to the soul, and health to the bones."
Book of Exodus The Book of Exodus (from grc, Ἔξοδος, translit=Éxodos; he, שְׁמוֹת ''Šəmōṯ'', "Names") is the second book of the Bible. It narrates the story of the Exodus, in which the Israelites leave slavery in Biblical Egypt through ...
famously describes the
Promised Land The Promised Land ( he, הארץ המובטחת, translit.: ''ha'aretz hamuvtakhat''; ar, أرض الميعاد, translit.: ''ard al-mi'ad; also known as "The Land of Milk and Honey"'') is the land which, according to the Tanakh (the Hebrew ...
as a "land flowing with milk and honey" (33:3). However, most Biblical commentators write that the original Hebrew in the Bible (דבש ''devash'') refers to the sweet syrup produced from the juice of dates (''silan''). In 2005 an apiary dating from the 10th century BC was found in Tel Rehov, Israel that contained 100 hives, estimated to produce half a ton of honey annually. Pure honey is considered kosher (permitted to be eaten by religious Jews), though it is produced by a flying insect, a non-kosher creature; eating other products of non-kosher animals is forbidden. It belongs among the ''parve'' (neutral) foods, containing neither meat nor dairy products and allowed to be eaten together with either. In Buddhism, honey plays an important role in the festival of '' Madhu Purnima'', celebrated in India and Bangladesh. The day commemorates Buddha's making peace among his disciples by retreating into the wilderness. According to legend, while he was there a monkey brought him honey to eat. On ''Madhu Purnima'', Buddhists remember this act by giving honey to
monks A monk (, from el, μοναχός, ''monachos'', "single, solitary" via Latin ) is a person who practices religious asceticism by monastic living, either alone or with any number of other monks. A monk may be a person who decides to dedic ...
. The monkey's gift is frequently depicted in Buddhist art. The Christian New Testament says that
John the Baptist John the Baptist or , , or , ;Wetterau, Bruce. ''World history''. New York: Henry Holt and Company. 1994. syc, ܝܘܿܚܲܢܵܢ ܡܲܥܡܕ݂ܵܢܵܐ, Yoḥanān Maʿmḏānā; he, יוחנן המטביל, Yohanān HaMatbil; la, Ioannes Bapti ...
lived for a long of time in the wilderness on a diet of locusts and honey.''Bible'', Matthew 3:4 In Islam, an entire chapter ( Surah) in the
Quran The Quran (, ; Standard Arabic: , Quranic Arabic: , , 'the recitation'), also romanized Qur'an or Koran, is the central religious text of Islam, believed by Muslims to be a revelation from God. It is organized in 114 chapters (pl.: , ...
is called ''
an-Nahl The Bee (Arabic: الْنَّحْل; ''an-nahl'') is the 16th chapter ('' sūrah'') of the Qur'an, with 128 verses ('' āyāt''). It is named after honey bees mentioned in verse 68, and contains a comparison of the industry and adaptability of ...
'' (the Bees). According to his teachings (''
hadith Ḥadīth ( or ; ar, حديث, , , , , , , literally "talk" or "discourse") or Athar ( ar, أثر, , literally "remnant"/"effect") refers to what the majority of Muslims believe to be a record of the words, actions, and the silent approva ...
''),
Muhammad Muhammad ( ar, مُحَمَّد;  570 – 8 June 632 CE) was an Arab religious, social, and political leader and the founder of Islam. According to Islamic doctrine, he was a prophet divinely inspired to preach and confirm the mon ...
strongly recommended honey for healing purposes.The Quran promotes honey as a nutritious and healthy food, saying:


See also

* Bee pollen * Honey hunting * List of spreads *
Mellivory Honey badgers (genus ''Mellivora'') are named for their diet of honey">Mellivora.html" ;"title="Honey badgers (genus ''Mellivora">Honey badgers (genus ''Mellivora'') are named for their diet of honey Mellivory is a term for the eating of honey. ...
* ''
More than Honey More or Mores may refer to: Computing * MORE (application), outline software for Mac OS * more (command), a shell command * MORE protocol, a routing protocol * Missouri Research and Education Network Music Albums * ''More!'' (album), by Booka ...
''a 2012 Swiss documentary film on the current state of honey bees and beekeeping * National Honey Show * Royal jelly


References


Bibliography

* *


External links


Beekeeping and Sustainable Livelihoods
(2004), Food and Agriculture Organization of the United Nations * {{Authority control Beekeeping Demulcents Non-timber forest products Sugar substitutes