Sweetness of wine

In contrast, the ancient Greeks would harvest the grapes early, to preserve some of their acidity, and then leave them in the sun for a few days to allow them to shrivel and concentrate the sugar.

In Crete, a similar effect was achieved by twisting the stalks of the grape to deprive them of sap and letting them dry on the vine—a method that produced passum and the modern Italian equivalent, passito.

[2] Wine can also be sweetened by the addition of sugar in some form, after fermentation is completed – the German method like the Süssreserve.

In Roman times, this was done in preparing mulsum, wine freshly sweetened with honey and flavored with spices, used as an apéritif, and also in the manufacture of conditum, which had similar ingredients but was matured and stored before drinking.

This means that the finest sweet wines are made with grape varieties that keep their acidity even at very high ripeness levels, such as Riesling and Chenin blanc.

A sweet wine such as a Vouvray can actually taste dry due to the high level of acidity.

However, many of the world's great wines, such as those from Sauternes (including Barsac) or Tokaj, have a high level of residual sugar, which is carefully balanced with additional acidity to produce a harmonious result.

Under German law, no more than fifteen percent of the final wine's volume may be the reserved juice.

[9] Article 58 points out "the sugar content may not differ by more than 3 grams per litre from what appears on the product label", so there is some leeway.

Alsace wines were the first to be described as Sélection de Grains Nobles, with the legal definition introduced in 1984.

In Germany, sweetness of must and wine is measured with the Oechsle scale, and below are ranges of minimum must weights for Riesling, depending on the region.