Sauvignon Blanc

Sauvignon Blanc is a French grape vine (Vitis vinifera) that is very widespread in France, the United States, South Africa, Australia and New Zealand. A variation is a rose grain, sauvignon gris, it has the same characteristics. Minor differences concern a greater ability to produce sweet wine or liqueur.
Young sauvignon blanc wines have a characteristic aroma, distinct from other varieties, whose descriptors are the main broom, boxwood, the bud of cassis, grapefruit, passion fruit and, in some cases, smoke, roast meat or flint. These highly fragrant molecules have been associated with thiol compounds (compounds carrying a function of sulfanyl, R-SH).

These flavors, as in the trace must, occur in wine during alcoholic fermentation. It is under the action of yeast (Saccharomyces cerevisiae) that volatile thiols are released from non-volatile precursors of the grape whose structures have been identified in S-conjugates as cysteine.
A study in 1997 revealed a direct relationship to cabernet sauvignon from the intersection of cabernet franc and sauvignon.

History
Sauvignon Blanc belongs to the Carmenet family, as does cabernet franc, cabernet sauvignon and merlot. According to Guy Lavignac, pilgrims returning to St. Jacques de Compostela had circulated a variety of the Spanish Basque country since the Middle Ages, probably the cabernet franc, ancestor of the family.
The sauvignon, as it has been known for centuries, is formally identified in the vineyards of Graves in 1736, and Pouilly-sur-Loire in 1783.
Long, its drawbacks are detrimental to their culture: sensitivity millerandage and mildew, difficulty harvesting (cluster without stem, glued to shoot), special flavorings. Since the 60s, advances in winemaking, the use of mechanical harvesting and a passion for aromatic dry white wines have encouraged plantings. In Bordeaux, it is poised to snatch the first place from Semillon vineyards in the Loire Valley, where it is also progressing. Its original flavor have made it very recognizable and interesting for wine country.

Geographical area

In France, sauvignon vineyards cover about 14,000 hectares, including 6,000 in the Southwest (including Bordeaux) and in the Loire Valley. This area is currently in progress. In the Loire Valley, it gives very dry white wine flavor (Sancerre, Pouilly-Fume). In Sauternes, when combined with Semillon and Muscadelle, Sauvignon allows obtaining sweet white wines. There is also steady growth in Languedoc for the production of wine grapes.
Ampelographic Characteristics:

The end of the young shoot is cottony, white to carmine rim.
Young leaves are yellow and fluffy.
The adult leaves, 5-lobed with lateral sinus, narrow and sharp funds, have a lyre-shaped petiolar sinus that is more or less open, ribbed teeth, narrow blade and fluffy.
The clusters and berries are small. The cluster is truncated, sometimes winged and compact. The berries are golden yellow with shades of green, except for the sauvignon berries that are gray or gray to pink.

Viticulture
Maturity is the second average time: 20 days after the Chasselas. It is a very vigorous vine, but it is very fertile. It requires a long pipe size. Its exuberant force needs to be controlled by an infertile soil, rootstock and low adjusting size and suckering its strength and sensitivity of clusters to botrytis.
Disease susceptibility
In addition to gray mold, this variety is concerned with powdery mildew, black rot and wood diseases (Eutypa dieback and esca). However, it is less sensitive to mildew. Susceptibility to gray mold can be used to develop sweet zones in climates conducive to the noble rot.

Technological potential

This wine is sweet with good acidity. The grape is versatile enough: in competition with the Semillon, it can produce sweet wines provided the winemaker allows the development of noble rot and reduced yields. The sauvignon gris has a greater capacity for accumulation of sugar, lower acidity, and more full-bodied and heavier aromas. It is particularly suitable for the preparation of sweet wines.
The aromas typical of sauvignon are boxwood or cat pee by the affinity of each with this scent. There are also citrus (grapefruit, lemon), white fruit (peach, pear), dried fruits (hazelnuts, almonds), mineral flavorings (flint, powder) in certain soils, and aromas such and honey and candied fruit due to noble rot decay.

Aromatic nuances

In 1995 the chemical nature of the main compounds responsible for the characteristic aroma of these wines has been identified. The discovery by Darriet et al of 4-methyl-4-sulfanylpentan-2-one (4MSP), with strong smell of boxwood and broom, opened the way for the identification of other flavors of the same chemical. The establishment of a specific method of purification of these compounds has, initially, been used to identify and quantify other compounds: acetate of 3-sulfanylhexanol (A3SH), which also evokes the boxwood smell, 4-methyl-4sulfanylpentan-2-ol (4MSPOH) and 3-sulfanylhexan-1-ol (3SH) more fruity nuances of grapefruit or passion fruit.

These flavors, as in the trace must, occur in wine during alcoholic fermentation. It is under the action of yeast (Saccharomyces cerevisiae) that volatile thiols are released from non-volatile precursors of the grape whose structures have been identified in S-conjugates to cysteine (Tominaga et al., 1998). The 4MSP the 4MSPOH and 3SH are thus released, respectively, from the S-4-(4-methyl-2-one)-L-cysteine (P-4MSP), S-4-(4 – methyl-2-ol)-L-cysteine (P-4MSPOH) and S-3-(hexan-1-ol)-L-cysteine (P-3SH).

The processing rate of precursors into cysteinyl thiol compounds during the fermentation is very low. Only 2 to 5% of precursors in the grape are transformed into volatile thiols by yeast. Moreover, the rate of transformation is highly dependent on the species or strain of yeast used. The yeast is largely responsible for the content of volatile thiols found in wines.

Finally, the presence of an S-3-(hexan-1-ol)-glutathione has been demonstrated (Peyrot des Gachon et al., 2000). The identification of this compound, which can be regarded as a pro-precursor, suggests that the S-3-(hexan-1-ol)-L-cysteine derived from the catabolism of S-3-(hexan-1-ol) is glutathione