Because the blue dye is not located in the juice of the wine berries, but in the shell, the mash is not immediately pressed, but directly fermented. The blue dye of the shells is extracted with the alcohol formed during fermentation. Alternatively, a thermal treatment for 60 to 87 oC is possible.
Following the alcoholic fermentation today mostly a biological acid degradation for the reduction of malic acid in red wine, which is converted into lactic acid, is performed. See malolactic fermentation
The content of ingredients and congeners in red wine is much higher than for white wine, because of other components of the berry skin are extracted. Thus, the content of flavanoids is about 10fold higher. The flavanoides oxidized during storage in bottles (oxygen entry through the cork) to longer chained molecules which are responsible for the characteristic taste of red wine.
The phenolic substances (polyphenols) are powerful antioxidants with demonstrable pharmacological effects with regular consumption: protection against atherosclerosis, reduction of LDL-cholesterol levels and increasement of HDL cholesterol, reducing risk of heart attack by preventing the formation of blood aggregates (thrombosis). In a bottle of red wine are 400 to 2000 mg flavanoides included.
The stilbene resveratrol, possibly effective against cancer cells and also tested as an anti-aging substance, is included in red wine in concentrations of 0.1 to 15 mg/l. Resveratrol may also control fat burning and thus avoid weight gain.
The polyphenols contained in red wine are now also available in capsule or tablet form, with 200 to 957 mg of red wine extract powder, but are free from alcohol.
Through gentle withdrawal of alcohol in a vacuum, the alcohol is withdrawn to a residual amount of about 0.2 per cent per volume. The content of aromatic substances, and particularly the valuable polyphenols is thereby maintained. See www.getraenke-ohne-alkohol.de (in German).