1.7 grams per litre. Sugars exercise a control over the taste – they balance the spiciness of the acidity and the burning of the alcohol. The organic acids The organic acids are mainly malic and tartaric acids. Tartaric acid is a characteristic of grapes; in its leaves its content ranges from 5 to 7 grams per litre. Malic acid is present in green grapes and its ratio decreases with maturation to give between 2 and 7 grams per litre at harvest. The range is very wide depending on the variety and soil with hot climates giving lower rates as the heat accelerates its degradation. There are many other acids in small quantities: citric acid, ascorbic acid, α-ketoglutaric, fumaric acid, galacturonic acid, coumaric acid, etc. Their variable quantity varies the pH of the wort. The must of white wine is generally more acidic than red grape must simply because the grape maturity is less advanced. Vitamins Vitamin C (or ascorbic acid) is present in the grape and the must up to 50 milligrams per litre. It is a protection in the wort against the oxidation phenomenon. In the presence of oxygen it produces hydrogen peroxide; by this reaction it deprives the enzymes in the wort of oxygen that is necessary to oxidize the wine. Since 1962 the addition of vitamin C in the wine has been allowed to a maximum of 15 grams per hectolitre at the time of packaging to stabilize the wine. Experiments in the late 2000s tried to determine a method to add it to fresh harvests or in the wort. Vitamin B1 or thiamine is present at a concentration between 0.2 and 0.5 milligrams per litre. This vitamin is necessary for the proper growth of yeasts that ensure alcoholic fermentation. In the must of healthy grapes the natural quantity is sufficient for the yeast. On the other hand, for a degraded harvest (by gray mold), the degradation of this vitamin leads the winemaker to add it to the must to ensure a trouble-free fermentation. In the case of a harvest with a very clear wort and low temperature the yeast works in a limited way and the addition of thiamine can help avoid a difficult end of fermentation. Legislation limits the amount added to 30 milligrams per hectolitre. The mineral elements The wort also contains minerals. Sodium, Potassium, and Magnesium are most common. Potassium and also calcium