![29-autunno,Taccuino Sanitatis, Casanatense 4182](https://upload.wikimedia.org/wikipedia/commons/a/a1/29-autunno%2CTaccuino_Sanitatis%2C_Casanatense_4182..jpg)
The
harvesting of
wine
Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are m ...
grape
A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus '' Vitis''. Grapes are a non- climacteric type of fruit, generally occurring in clusters.
The cultivation of grapes began perhaps 8,000 years a ...
s (
Vintage
Vintage, in winemaking, is the process of picking grapes and creating the finished product—wine (see Harvest (wine)). A vintage wine is one made from grapes that were all, or primarily, grown and harvested in a single specified year. In certa ...
) is one of the most crucial steps in the process of
wine-making
Winemaking or vinification is the production of wine, starting with the selection of the fruit, its fermentation into alcohol, and the bottling of the finished liquid. The history of wine-making stretches over millennia. The science of wine and w ...
. The time of harvest is determined primarily by the
ripeness of the grape as measured by
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 double ...
,
acid
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
and
tannin
Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids.
The term ''tannin'' (from Anglo-Norman ''tanner'', ...
levels with winemakers basing their decision to pick based on the style of wine they wish to produce. The
weather
Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the ...
can also shape the timetable of harvesting with the threat of heat, rain, hail, and frost which can damage the grapes and bring about various
vine disease
This is a list of diseases of grapes (''Vitis'' spp.).
Bacterial diseases
Fungal diseases
Miscellaneous diseases and disorders
Nematodes, parasitic
Phytoplasma, virus and viruslike diseases
See also
*'' Ampeloglypter ater''
*'' Am ...
s. In addition to determining the time of the harvest, winemakers and vineyard owners must also determine whether to use hand pickers or
mechanical harvesters. The harvest season typically falls between August & October in the
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
and February & April in the
Southern Hemisphere. With various climate conditions,
grape varieties
This list of grape varieties includes cultivated grapes, whether used for wine, or eating as a table grape, fresh or dried (raisin, currant, sultana). For a complete list of all grape species including those unimportant to agriculture, see Viti ...
, and wine styles the harvesting of grapes could happen in every month of the calendar year somewhere in the world. In the
New World
The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. 3 ...
it is often referred to as the ''crush''.
[J. Robinson (ed) ''"The ]Oxford
Oxford () is a city in England. It is the county town and only city of Oxfordshire. In 2020, its population was estimated at 151,584. It is north-west of London, south-east of Birmingham and north-east of Bristol. The city is home to the ...
Companion to Wine"'' Third Edition pg 338-339 Oxford University Press 2006
Harvest season
The majority of the world's
wine producing regions lie between the
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...
latitude
In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...
s of 30° and 50° in both hemispheres with regions lying closer to the
equator
The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can als ...
typically harvesting earlier due to their warmer climates. In the Northern Hemisphere, vineyards in
Cyprus
Cyprus ; tr, Kıbrıs (), officially the Republic of Cyprus,, , lit: Republic of Cyprus is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. Its continental position is disputed; while it is geo ...
begin harvesting as early as July. In California some
sparkling wine
Sparkling wine is a wine with significant levels of carbon dioxide in it, making it fizzy. While the phrase commonly refers to champagne, European Union countries legally reserve that term for products exclusively produced in the Champagne regi ...
grapes are harvested in late July to early August at a slightly unripe point to help maintain
acidity
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
in the wine. The majority of Northern Hemisphere harvesting occurs in late August to early October with some
late harvest wine
Late harvest wine is wine made from grapes left on the vine longer than usual. ''Late harvest'' is usually an indication of a sweet dessert wine, such as late harvest Riesling. Late harvest grapes are often more similar to raisins, but have been ...
grapes being harvested throughout the autumn. In Germany, Austria, the United States and Canada,
ice wine
Ice wine (or icewine; german: Eiswein) is a type of dessert wine produced from grapes that have been frozen while still on the vine. The sugars and other dissolved solids do not freeze, but the water does, allowing for a more concentrated grape ...
grapes can be harvested as late as January. In the Southern Hemisphere harvest can begin as early as January 1 in some of the warmer climate sites in
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
, Australia. The majority of Southern Hemisphere harvesting occurs between the months of February and April with some cool climate sites like
Central Otago, New Zealand picking late harvest wine grapes in June.
Recent
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
s (particularly
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
) have shifted the harvest season in some countries ; future weather patterns may exceed a climatic threshold in some vineyards where it will be more difficult to maintain the current wine quality, however they could also push some regions into more optimal climatic regimes for the production of equilibred grapes.
Ripeness
![OV-pinot-noir](https://upload.wikimedia.org/wikipedia/commons/0/0c/OV-pinot-noir.jpg)
Throughout the
history of wine
Wine has been produced for thousands of years, with evidence of ancient wine production in Georgia from BC (the earliest known traces of wine),
West Azerbaijan province of Iran from BC, Armenia from BC (large-scale production), and Sicil ...
, winemakers would use 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 double ...
and acid levels of the grape as a guide in determining ripeness. Early winemakers tasted the grapes to gauge ripeness. Modern winemakers use a
refractometer
A refractometer is a laboratory or field device for the measurement of an index of refraction ( refractometry). The index of refraction is calculated from the observed refraction angle using Snell's law. For mixtures, the index of refraction the ...
to measure high sugar levels and
°Brix or
titration
Titration (also known as titrimetry and volumetric analysis) is a common laboratory method of quantitative chemical analysis to determine the concentration of an identified analyte (a substance to be analyzed). A reagent, termed the ''titrant'' ...
tests (using an indicator such as
phenolphthalein
Phenolphthalein ( ) is a chemical compound with the formula C20 H14 O4 and is often written as "HIn", "HPh", "phph" or simply "Ph" in shorthand notation. Phenolphthalein is often used as an indicator in acid–base titrations. For this applica ...
) to determine the
titratable acidity within the grape.
In recent times there has been more of an emphasis on the "physiological" ripeness of the grape, usually in the form of tannins and other
phenolics.
[J. Robinson ''Jancis Robinson's Wine Course'' Third Edition pg 75 Abbeville Press 2003 ] Currently, tasting is the only way to measure tannin ripeness, which can take experience and skill to do accurately.
Viticulturalists have not yet fully explained the complex processes that go into the ripening of tannins but most believe it begins with the
polymerization
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many fo ...
of small
astringent
An astringent (sometimes called adstringent) is a chemical that shrinks or constricts body tissues. The word derives from the Latin ''adstringere'', which means "to bind fast". Calamine lotion, witch hazel, and yerba mansa, a Californian plant ...
tannins into larger molecules which are perceived by the
taste bud
Taste buds contain the taste receptor cells, which are also known as gustatory cells. The taste receptors are located around the small structures known as lingual papillae, papillae found on the upper surface of the tongue, soft palate, upper e ...
s as being
softer.
[K. MacNeil ''The Wine Bible'' pg 10-11 Workman Publishing 2001 ]
Mechanical harvesting
![Mechanical Grape Harvester1](https://upload.wikimedia.org/wikipedia/commons/2/26/Mechanical_Grape_Harvester1.JPG)
The question of using mechanical harvesting versus traditional hand picking is a source of contention in the wine industry. Mechanical harvesting of grapes has been one of the major changes in many
vineyard
A vineyard (; also ) is a plantation of grape-bearing vines, grown mainly for winemaking, but also raisins, table grapes and non-alcoholic grape juice. The science, practice and study of vineyard production is known as viticulture. Vineyards ...
s in the last third of a century. First introduced commercially in the 1960s, it has been adopted in different wine regions for various economic, labor and winemaking reasons. In Australia, the reduced work force in the wine industry has made the use of mechanized labor almost a necessity.
A mechanical grape harvester works by beating the
vine
A vine (Latin ''vīnea'' "grapevine", "vineyard", from ''vīnum'' "wine") 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 themselv ...
with rubber sticks to get the vine to drop its fruit onto a conveyor belt that brings the fruit to a holding bin. As technology improves mechanical harvesters have become more sophisticated in distinguishing grape clusters from mud, leaves and other particles. Despite the improvement many harvesters still have difficulties in distinguishing between ripe, healthy grapes and unripe or rotted bunches which must then be sorted out at the winemaking facility. Another disadvantage is the potential of damaging the grape skins which can cause
maceration and coloring of the juice that is undesirable in the production of white and sparkling wine. The broken skins also bring the risk of
oxidation
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
and a loss of some of the aromatic qualities in the wine.
[T. Stevenson ''"The Sotheby's Wine Encyclopedia"'' pg 22 Dorling Kindersley 2005 ]
One of the benefits of mechanical harvesting is the relatively low cost. A harvester is able to run 24 hours a day and pick 80–200
ton
Ton is the name of any one of several units of measure. It has a long history and has acquired several meanings and uses.
Mainly it describes units of weight. Confusion can arise because ''ton'' can mean
* the long ton, which is 2,240 pounds
...
s of grapes, compared to the 1–2 tons that an experienced human picker could harvest. In hot climates, where picking quickly or in the cool of night is a priority, mechanical harvesting can accomplish these goals very well.
[K. MacNeil ''The Wine Bible'' pg 28 Workman Publishing 2001 ]
Hand picking
![Gruner Veltliner grapes being hand harvested at Hahndorf Hill vineyard in the Adelaide Hills](https://upload.wikimedia.org/wikipedia/commons/8/8f/Gruner_Veltliner_grapes_being_hand_harvested_at_Hahndorf_Hill_vineyard_in_the_Adelaide_Hills.jpg)
Despite the costs, some wineries prefer the use of human workers to hand-pick grapes. The main advantage is the knowledge and discernment of the worker to pick only healthy bunches and the gentler handling of the grapes. The production of some
dessert wine
Dessert wines, sometimes called pudding wines in the United Kingdom, are sweet wines typically served with dessert.
There is no simple definition of a dessert wine. In the UK, a dessert wine is considered to be any sweet wine drunk with a meal ...
like
Sauternes and
Trockenbeerenauslese
''Trockenbeerenauslese'' (literal meaning: 'dried berry selection') is a German language wine term for a medium to full body dessert wine.
''Trockenbeerenauslese'' is the highest in sugar content in the ''Prädikatswein'' category of the Austrian ...
require that individual berries are picked from the
botrytized
''Botrytis cinerea'' is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as "botrytis bunch rot"; in horticulture, it is usually called "grey mould" o ...
bunches which can only be done by hand. In areas of steep terrain, like in the
Mosel, it would be virtually impossible to run a mechanical harvester through the vineyard. In many wine regions,
migrant worker
A migrant worker is a person who Human migration, migrates within a home country or outside it to pursue work. Migrant workers usually do not have the intention to stay permanently in the country or region in which they work.
Migrant worker ...
s are a sizable composition of the harvest time work force as well as local student and itinerant workers.
Karen Ross, president of the California Association of Winegrowers, has estimated that as of 2007 as many as 70% of the employees in the
California wine
California wine production has a rich viticulture history since 1680 when
Spanish Jesuit missionaries planted ''Vitis vinifera'' vines native to the Mediterranean region in their established missions to produce wine for religious services. I ...
industry may be immigrants from Mexico.
[D. Sogg ''"Immigration Rules May Cause Higher Wine Prices"'' The Wine Spectator pg 16 October 31st, 2007.]
References
{{portal bar, Drink
Oenology
Harvest
Viticulture
Wine