HOME

TheInfoList



OR:

''Humulus'', or hop, is a small
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
s in the
family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Cannabaceae Cannabaceae is a small family of flowering plants, known as the hemp family. As now circumscribed, the family includes about 170 species grouped in about 11 genera, including '' Cannabis'' (hemp), '' Humulus'' (hops) and '' Celtis'' (hackberri ...
. The hop is
native Native may refer to: People * '' Jus sanguinis'', nationality by blood * '' Jus soli'', nationality by location of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Nat ...
to
temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...
regions of the Northern Hemisphere.
Hops Hops are the flowers (also called seed cones or strobiles) of the hop plant ''Humulus lupulus'', a member of the Cannabaceae family of flowering plants. They are used primarily as a bittering, flavouring, and stability agent in beer, to whic ...
are the female flowers (seed cones, strobiles) of the hop
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
'' H. lupulus''; as a main flavor and aroma ingredient in many
beer Beer is an alcoholic beverage produced by the brewing and fermentation of starches from cereal grain—most commonly malted barley, although wheat, maize (corn), rice, and oats are also used. The grain is mashed to convert starch in the ...
styles, ''H. lupulus'' is widely cultivated for use by the brewing industry.


Description

Although frequently referred to in American literature as the hops "vine", it is technically a bine; unlike
vine A vine is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas, or runners. The word ''vine'' can also refer to such stems or runners themselves, for instance, when used in wicker work.Jackson; Benjamin; Da ...
s, which use
tendril In botany, a tendril is a specialized Plant stem, stem, leaf or Petiole (botany), petiole with a thread-like shape used by climbing plants for support and attachment, as well as cellular invasion by parasitic plants such as ''Cuscuta''. There ar ...
s, suckers, and other appendages for attaching themselves, bines have stout stems with stiff hairs to aid in climbing. In British literature the term "vine" is generally reserved for the grape genus ''
Vitis ''Vitis'' (grapevine) is a genus of 81 accepted species of vining plants in the flowering plant family Vitaceae. The genus consists of species predominantly from the Northern Hemisphere. It is economically important as the source of grapes, bot ...
''. ''Humulus'' is described as a twining
perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...
herbaceous plant Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition o ...
which sends up new shoots in early spring and dies back to the cold-hardy
rhizome In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...
in autumn. Hop shoots grow very rapidly, and at the peak of growth can grow per week. Hop bines climb by wrapping clockwise (except for ''
Humulus japonicus ''Humulus japonicus'', known as Japanese hops, is an ornamental plant in the family Cannabaceae. Some authorities have it as a synonym of ''Humulus scandens''. Originally native to East Asian countries such as China, Japan, Korea, and extending ...
'') around anything within reach, and individual bines typically grow between depending on what is available to grow on. The
leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...
are opposite, with a leafstalk and a heart-shaped, fan-lobed blade long and broad; the edges are coarsely toothed. When the hop bines run out of material to climb, horizontal shoots sprout between the leaves of the main stem to form a network of stems wound round each other. Male and female flowers of the hop plant are
dioecious Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...
, developing on separate plants. Female plants, which produce the hop flowers used in brewing beer, are often propagated vegetatively and grown in the absence of male plants. This prevents pollination and the development of viable
seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...
s, which are sometimes considered undesirable for brewing beer owing to the potential for off-flavors arising from the introduction of fatty acids from the seeds. The characteristic bitterness imparted by the addition of hops to the brewing process is mainly due to the presence of bitter acids, which are prenylated acylphloroglucinol derivatives. Bitter acids are divided into the alpha-acids, with humulone the major compound, and the beta-acids, with lupulone the major compound; the alpha-acids isomerize during the brewing process to form iso-alpha acids, which themselves have a bitter taste. These hop acids are vinylogous acids, with acidic ring enols in conjugation with ring and substituent carbonyl groups. Plants in the genus ''Humulus'' produce terpenophenolic metabolites. Hops also contain xanthohumol, a prenylated
chalcone Chalcone is the organic compound C6H5C(O)CH=CHC6H5. It is an α,β-unsaturated ketone. A variety of important biological compounds are known collectively as chalcones or chalconoids. They are widely known bioactive substances, fluorescent materi ...
, and other compounds.


Taxonomy

, the following species were accepted: *'' Humulus americanus'' Nutt. *'' Humulus cordifolius'' Miq. *'' Humulus lupulus'' L. *'' Humulus neomexicanus'' (A.Nelson & Cockerell) Rydb. *'' Humulus pubescens'' (E.Small) Tembrock *'' Humulus scandens'' (Lour.) Merr. (syn. ''
Humulus japonicus ''Humulus japonicus'', known as Japanese hops, is an ornamental plant in the family Cannabaceae. Some authorities have it as a synonym of ''Humulus scandens''. Originally native to East Asian countries such as China, Japan, Korea, and extending ...
Siebold & Zucc.) *'' Humulus yunnanensis'' Hu For brewers' hops, which are specific cultivars, and propagated by
asexual reproduction Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the f ...
, see the article, "
List of hop varieties This is a list of varieties of hop ('' Humulus lupulus''). As there are male and female plants, the flowers (cones) of the female plant are fertilized by the pollen of the male flowers with the result that the female flowers form seeds. These ...
".


Uses

Hops are boiled with the
wort Wort () is the liquid extracted from the mashing process during the brewing of beer or whisky. Wort contains the sugars, the most important being maltose and maltotriose, that will be Ethanol fermentation, fermented by the brewing yeast to prod ...
in
brewing Brewing is the production of beer by steeping a starch source (commonly cereal grains, the most popular of which is barley) in water and #Fermenting, fermenting the resulting sweet liquid with Yeast#Beer, yeast. It may be done in a brewery ...
beer and sometimes added post-ferment; they impart a bitterness, flavor, as well as aroma to the finished product. In
pharmacy Pharmacy is the science and practice of discovering, producing, preparing, dispensing, reviewing and monitoring medications, aiming to ensure the safe, effective, and affordable use of medication, medicines. It is a miscellaneous science as it ...
''lupulus'' is the designation of hop. The dried
catkin A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind- pollinated ( anemophilous) but sometimes insect-pollinated (as in '' Salix''). It contains many, usually unisexual flowers, arra ...
s, commonly referred to as hop cones, of the female plant of ''H. lupulus'' are used to prepare
infusion Infusion is the process of extracting chemical compounds or flavors from plant material in a solvent such as water, oil or alcohol, by allowing the material to remain suspended in the solvent over time (a process often called steeping). An inf ...
of hop,
tincture A tincture is typically an extract of plant or animal material dissolved in ethanol (ethyl alcohol). Solvent concentrations of 25–60% are common, but may run as high as 90%.Groot Handboek Geneeskrachtige Planten by Geert Verhelst In chemistr ...
of hop, and
extract An extract (essence) is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures or absolutes or dried and powdered. The aromatic principles of ma ...
of hop. Some of the compounds hops contain are under preliminary research for their potential health properties.


References


External links


Jeanine S. DeNoma: ''Humulus Genetic Resources'' (USDA ARS National Clonal Germplasm Repository)



Plants for a Future: ''Humulus lupulus''
{{Authority control Medicinal plants Stem vegetables Dioecious plants Rosales genera Taxa named by Carl Linnaeus