The harvest

Harvest

Harvest is the process of gathering mature crops from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle, or reaper...

ing of wine

Wine

Wine is an alcoholic beverage, made of fermented fruit juice, usually from grapes. The natural chemical balance of grapes lets them ferment without the addition of sugars, acids, enzymes, or other nutrients. Grape wine is produced by fermenting crushed grapes using various types of yeast. Yeast...

 grapes (Vintage

Vintage

Vintage, in wine-making, is the process of picking grapes and creating the finished product . A vintage wine is one made from grapes that were all, or primarily, grown and harvested in a single specified year. In certain wines, it can denote quality, as in Port wine, where Port houses make and...

) is one of the most crucial steps in the process of winemaking

Winemaking

Winemaking, or vinification, is the production of wine, starting with selection of the grapes or other produce and ending with bottling the finished wine. Although most wine is made from grapes, it may also be made from other fruit or non-toxic plant material...

. The time of harvest is determined primarily by the ripeness

Ripening

Ripening is a process in fruits that causes them to become more palatable. In general, a fruit becomes sweeter, less green, and softer as it ripens. Even though the acidity of fruit increases as it ripens, the higher acidity level does not make the fruit seem tarter, which can lead to the...

 of the grape as measured by sugar

Sugar

Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...

, acid

Acid

An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

 and tannin levels with winemakers basing their decision to pick based on the style of wine they wish to produce. The weather

Weather

Weather is the state of the atmosphere, to the degree that it is hot or cold, wet or dry, calm or stormy, clear or cloudy. Most weather phenomena occur in the troposphere, just below the stratosphere. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate...

 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 diseases. In addition to determining the time of the harvest, winemakers and vineyard owners must also determine whether to utilize hand pickers or mechanical harvesters

Mechanised agriculture

Mechanized agriculture is the process of using agricultural machinery to mechanize the work of agriculture, massively increasing farm output and farm worker productivity...

. The harvest season typically falls between August & October in the Northern Hemisphere

Northern Hemisphere

The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...

 and February & April in the Southern Hemisphere

Southern Hemisphere

The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...

. With various climate conditions, grape varieties, and wine styles the harvesting of grapes could happen in every month of the calendar year somewhere in the world. In the New World

New World

The New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...

 it is often referred to as the crush.

Harvest season

The majority of the world's wine producing regions lie between the temperate

Temperate

In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...

 latitudes of 30° and 50° in both hemispheres

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 with regions lying closer to the equator

Equator

An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....

 typically harvesting earlier due to their warmer climates. In the Northern Hemisphere, vineyards in Cyprus

Cyprus

Cyprus , officially the Republic of Cyprus , is a Eurasian island country, member of the European Union, in the Eastern Mediterranean, east of Greece, south of Turkey, west of Syria and north of Egypt. It is the third largest island in the Mediterranean Sea.The earliest known human activity on the...

 begin harvesting as early as July. In California some sparkling wine

Sparkling wine

Sparkling wine is a wine with significant levels of carbon dioxide in it making it fizzy. The carbon dioxide may result from natural fermentation, either in a bottle, as with the méthode champenoise, in a large tank designed to withstand the pressures involved , or as a result of carbon dioxide...

 grapes are harvested in late July to early August at a slightly unripe point to help maintain acidity

Acids in wine

The acids in wine are an important component in both winemaking and the finished product of wine. They are present in both grapes and wine, having direct influences on the color, balance and taste of the wine as well as the growth and vitality of yeasts during fermentation and protecting the wine...

 in the wine. The majority of Northern Hemisphere harvesting occurs in late August to early October with some late harvest wine

Late harvest wine

Late harvest is a term applied to wines 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 naturally dehydrated while on the vine...

 grapes being harvested throughout the autumn. In Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, the U.S. and Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, ice wine

Ice wine

Ice wine 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 a more concentrated grape must to be pressed from the frozen grapes, resulting in a smaller amount of more...

 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

New South Wales

New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. The majority of Southern Hemisphere harvesting occurs between the months of February and April with some cool climate sites like Central Otago

Central Otago

Central Otago is the inland part of the New Zealand region of Otago in the South Island. The area commonly known as Central Otago includes both the Central Otago District and the Queenstown-Lakes District to the west....

, New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

 picking late harvest wine grapes in June.

Ripeness

Throughout the history of wine

History of wine

The history of wine spans thousands of years and is closely intertwined with the history of agriculture, cuisine, civilization and humanity itself...

, winemakers would use the sugar

Sugars in wine

The sugars in wine grapes are what make winemaking possible. During the process of fermentation, sugars are broken down and converted by yeasts into alcohol and carbon dioxide. Grapes accumulate sugars as they grow on the grapevine through the translocation of sucrose molecules that are produced...

 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

Refractometer

A refractometer is a laboratory or field device for the measurement of an index of refraction . The index of refraction is calculated from Snell's law and can be calculated from the composition of the material using the Gladstone-Dale relation....

 to measure sugar levels and °Brix or titration

Titration

Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Because volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the...

 tests (using an indicator such as phenolphthalein

Phenolphthalein

Phenolphthalein is a chemical compound with the formula C20H14O4 and is often written as "HIn" or "phph" in shorthand notation. Often used in titrations, it turns colorless in acidic solutions and pink in basic solutions...

) 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

Phenolic compounds in wine

The phenolic compounds - natural phenol and polyphenols - in wine include a large group of several hundred chemical compounds that affect the taste, color and mouthfeel of wine. These compounds include phenolic acids, stilbenes, flavonols, dihydroflavonols, anthocyanins, flavanol monomers and...

. Currently, tasting is the only way to measure tannin ripeness, which can take experience and skill to do accurately. Viticulturalists

Viticulture

Viticulture is the science, production and study of grapes which deals with the series of events that occur in the vineyard. When the grapes are used for winemaking, it is also known as viniculture...

 have not yet fully explained the complex processes that go into the ripening of tannins but most believe it begins with the polymerization

Polymerization

In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains...

 of small astringent

Astringent

An astringent substance is a chemical compound that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin adstringere, meaning "to bind fast"...

 tannins into larger molecules which are perceived by the taste buds as being softer.

Mechanical harvesting

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

Vineyard

A vineyard is a plantation of grape-bearing vines, grown mainly for winemaking, but also raisins, table grapes and non-alcoholic grape juice...

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 reason. In Australia, the reduced work force in the wine industry has made the use of mechanized labor almost a necessity.

A mechanical vine harvester works by beating the vine

Vine

A vine in the narrowest sense is the grapevine , but more generally it can refer to any plant with a growth habit of trailing or scandent, that is to say climbing, stems or runners...

 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

Maceration (wine)

Maceration is the winemaking process where the phenolic materials of the grape— tannins, coloring agents and flavor compounds— are leached from the grape skins, seeds and stems into the must. Maceration is the process by which the red wine receives its red color, since 99% of all grape juice is...

 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 and a loss of some of the aromatic qualities in the wine.

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

The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.It is derived from...

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.

Hand picking

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 wine

Dessert wines 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, as opposed to the white fortified wines drunk before the meal, and the red fortified wines drunk after it...

 like Sauternes

Sauternes (wine)

Sauternes is a French sweet wine from the Sauternais region of the Graves section in Bordeaux. Sauternes is made from Sémillon, Sauvignon Blanc, and Muscadelle grapes that have been affected by Botrytis cinerea, also known as noble rot. This causes the grapes to become partially raisined,...

 and Trockenbeerenauslese

Trockenbeerenauslese

Trockenbeerenauslese is a German language wine term for an intensely sweet dessert wine-style wine....

 require that individual berries are picked from the botrytized bunches which can only be done by hand. In areas of steep terrain, like in the Mosel

Moselle River

The Moselle is a river flowing through France, Luxembourg, and Germany. It is a left tributary of the Rhine, joining the Rhine at Koblenz. A small part of Belgium is also drained by the Mosel through the Our....

, it would be virtually impossible to run a mechanical harvester through the vineyard. In many wine regions, migrant worker

Migrant worker

The term migrant worker has different official meanings and connotations in different parts of the world. The United Nations' definition is broad, including any people working outside of their home country...

s are a sizable composition of the harvest time work force as well as local student and itinerant

Itinerant

An itinerant is a person who travels from place to place with no fixed home. The term comes from the late 16th century: from late Latin itinerant , from the verb itinerari, from Latin iter, itiner ....

 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

California wine has a long and continuing history, and in the late twentieth century became recognized as producing some of the world's finest wine. While wine is made in all fifty U.S. states, up to 90% of American wine is produced in the state...

 industry may be immigrants from Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

.