Acids in wine responsible for the sour taste of vinegar. During fermentation, activity by yeast cells naturally produces a small amount of acetic acid. If the wine is exposed to oxygen, "Acetobacter" bacteria will convert the ethanol into acetic acid. This process is known as the “acetification” of wine and is the primary process behind wine degradation into vinegar. An excessive amount of acetic acid is also considered a wine fault. A taster's sensitivity to acetic acid will vary, but most people can detect excessive amounts at around 600 mg/l. Ascorbic acid, also known as vitamin C, is found in young wine grapes
History of French wine the close commercial ties with the English allowing this area to grow in prominence among all French wines. In the aftermath of the Hundred Years War, these lands reverted to French rule but with a lasting imprint of English influence. Following the restoration of Charles II to the British crown, several French wines came back into fashion in the London market. One such wine was a fizzy drink from the Champagne region that was disparaged among French wine drinkers for its faulty bubbles. A French expatriate, Charles de Saint-Évremond, introduced this sparkling style of Champagne to the London court and