Name for hydrogen-containing, liquid or solid chemical compounds. The hydrogen ions cause the sourtaste a solution. One distinguishes between inorganic and Organic acids, In the wine are mostly organic acids of the group carboxylic acids in free, bound and to a lesser extent also in volatile form. The term "acid" is not meant to be negative, because without this important ingredient, a wine tastes good flat and slow. Only then does he get refreshing power, and that is just the reason for that Sweet to better advantage. Wines from hot areas often have a lower content. Not mature grapes own different depending vine a high proportion.