Viticulture

A great number of varieties are now approved in the European Union as true grapes for winegrowing and viticulture.

[5] Evidence suggests that some of the earliest domestication of Vitis vinifera occurred in the area of the modern countries Georgia and Armenia.

Dated to c. 4100 BC, the site contained a wine press, fermentation vats, jars, and cups.

Nearby lakes and rivers can serve as protection for drastic temperature drops at night by releasing the heat that the water has stored during the day to warm the vines.

[17] Although the skin contains the majority of the tannin, small percentages can be found throughout the grape and during all of its developmental stages.

However, the tannin's most important role is during the grape's ripening stage as its function is to formulate color and body shape.

[16] Although many factors can affect the overall quality of a grape vine, the three most important are climate, slope, and soil,[18] often collectively referred to as the terroir.

Additionally, because climatic factors such as temperature and rain can be unpredictable and uncontrollable, each year will produce unique qualities and yields of grapes.

In ideal circumstances, the vine will receive most of the rainfall during the winter and spring months: rain at harvesttime can create many hazards, such as fungal diseases and berry splitting.

[21] These climates allow grapes to ripen faster with higher sugar levels and lower acidity.

Cooler seasons force the grapes to ripen earlier, which produces a fresher and more acidic harvest.

[21] Additionally, a slope affords better drainage, obviating the possibility that the vine might sit in overly moist soil.

[24] Favorable soil conditions include: aeration, loose texture, good drainage and moderate fertility.

[23] A viticulturist faces many hazards that can have an adverse effect on the wine produced from the grape or kill the vine itself.

A green harvest is the removal of immature grape bunches, typically for the purpose of decreasing yield.

In the absence of a green harvest, a healthy, vigorous vine can produce dilute, unripe grapes.

[citation needed] In Europe, many appellations restrict the yield permitted from a given area, so there is even more incentive to perform green harvesting when presented with excess crop.

Gemischter Satz (Mixed set) is a wine term in German equivalent to a field blend, which means that grapes of different varieties are planted, harvested and vinified together.