Definition: grape variety (various types)

However, it is important to note that:

Vitis labrusca is cultivated for wine in North America, particularly on the east coast of the United States and in Canada; but the resulting wine has a distinctive smell and taste, known as 'foxed', which is reminiscent of raspberries at first, followed by a very acrid, rather unpleasant aftertaste; sometimes referred to as 'noahté', from the name of the Noah grape variety that was once widespread in Europe;

Some Asian species cultivated in China, Korea and Japan are capable of producing a drinkable wine when nothing better is available. For example, when good wine was in short supply at the height of the phylloxera crisis, Japan exported wine made from Vitis coignetiae.

Vitis riparia, Vitis rupestris, and Vitis berlandieri, all three of American origin, are very important for viticulture because they are the most resistant to phylloxera and for this reason are used as rootstocks for Vitis vinifera. Similarly, hybrids derived from Vitis candicans, native to the Mississippi swamps, are sometimes chosen as rootstocks because of their resistance to soils with excessive salt content. Returning to Vitis vinifera, which is of most interest to us, it seems to originate from Transcaucasia, but it was in the warm regions of the Mediterranean basin that it particularly thrived and developed, domesticated by the earliest civilisations. This species includes many varieties (grape varieties) that have a natural tendency to reproduce and cross-pollinate. Since the dawn of civilisation, the primary effort of winegrowers has been to control or encourage cross-pollination, seeking to obtain grape varieties with a number of desirable properties. Nowadays, the complex task of searching for new varieties is carried out by specialised laboratories, and the reproduction of selected varieties is handled by nurseries.

Ampelography, which identifies grape varieties by their shoots and leaves, distinguishes some 5,000 varieties with certainty and acknowledges the difficulty of identifying and classifying an infinite number of sub-varieties obtained by chance through local evolution or through increasingly refined selection in laboratories. In addition to natural or induced crosses between varieties of the Vitis vinifera species, hybrids have been created, either between varieties of Vitis vinifera and Vitis labrusca, or even between hybrids and Vitis vinifera.

Essentially, the creation of hybrids was justified by the difficulty of acclimatising the good European Vitis vinifera in America, and secondarily wherever there was a desire, rightly or wrongly, to grow vines in cold climates such as Germany or Great Britain, or humid climates such as Brazil, for example. Around 500 grape varieties are of definite oenological interest. However, only around fifteen varieties are capable of producing excellent wines almost anywhere in the world. Main red grape varieties: Cabernet Franc, Cabernet Sauvignon, Gamay, Grenache Noir, Malbec, Merlot, Pinot Noir, Syrah.

Main white grape varieties: Chardonnay, Gewurztraminer, Muscat, Pinot Gris, Riesling.

Alongside these exceptional varieties, there are dozens of others that are excellent in their chosen terroir but do not easily acclimatise elsewhere. Among the best of these are:

Red varieties: Mourvèdre, Nebbiolo, Sangiovese, Tempranillo, Zinfandel - White varieties: Chenin, Furmint, Palomino Fino, etc.

In total, there are enough of them to raise the question, which is still being asked in many wine-growing areas, of which grape variety or varieties are the most suitable. What are the criteria for making this choice? Far from the somewhat academic considerations governing the classification of grape varieties according to their graphic description or origin, winegrowers and winemakers assess grape varieties according to criteria that are of practical interest to their daily lives. For them, the main characteristics of a grape variety are the climate and soil that suit it, and the quantity and quality of the must it produces.

More generally, there are two main practical classifications of grape varieties:

1 According to purpose

The type of wine to be produced determines the choice of certain grape varieties that are more suitable than others for producing that type of wine. Thus:

Chasselas produces an excellent table grape, but a fairly ordinary wine, except in Switzerland, where ancestral know-how and terroir produce wines of great finesse;

Ugni Blanc, undoubtedly the most widely grown grape variety in the world, produces an ordinary wine and is therefore often distilled;

Muscat is particularly suited to producing sweet wines known as natural wines, although these are obtained by interrupting fermentation early by adding alcohol;

Some very sweet grape varieties, such as Sémillon, are suitable for producing sweet wines, while others that are also very sweet are better suited to producing dry wines with a high alcohol content.

While most grape varieties produce wines that are best drunk young, a few can be used to make wines that can be stored for a long time.

A few grape varieties are well suited to the production of sparkling wines.

a handful of grape varieties produce special wines such as sherry or vin jaune, which develop under the protection of the "flor" created by yeasts during fermentation;

obviously, white grapes can only produce white wines, while black grapes offer complete freedom in terms of the final colour of the wine, whether white, rosé or red;

most lower-quality grape varieties, and some of the best varieties, produce more satisfactory results in more or less complex blends; only a few high-quality grape varieties encourage the production of single-varietal wines, etc.

According to ripening date (precociousness)

The Pulliat classification, named after the Frenchman who established it at the end^{of the 19th} century, classifies grape varieties into five categories according to their ripening date (i.e. when the sugar content of the grapes has reached its maximum and is no longer increasing), using Chasselas Doré as a reference:

1. early-ripening grape varieties, reaching maturity 10 days before golden Chasselas;

2. Early-ripening varieties, reaching maturity at around the same time as Chasselas;

3. Second-period varieties, which finish ripening 12 days later;

4. third-period varieties, 24 days after Chasselas doré;

5. and late varieties, which ripen 36 days after Chasselas.

The Pulliat classification was improved by the Americans Winkler and Amerine, who determined the total amount of heat each grape variety requires to reach maturity, and in California, the University of Davis has made very important practical applications of this.

In cold climates, early-ripening grape varieties are chosen, capable of ripening before the autumn cold sets in. Warm climates allow the use of later-ripening grape varieties, which are also more productive. However, very hot climates are unsuitable for producing good grapes, as the vines receive too much sun and not enough soil. In all cases, ripening must not be too rapid, as the best wines come from grape varieties that are just ripe, with all the risks that this entails. Therefore, the grape variety is not everything, and the INAO (Institut National des Appellations d'Origine) rightly maintains that each AOC owes its specificity to a combination of factors, among which the terroir plays a key role.