Deteriorative Changes in Wine ¹

Abstract

SINCE the time when Pasteur, in his“Études sur le Vin,” described a. certain bitterness sometimes occurring in wine (Maladie de l'amertume) as being apparently due to a specific microorganism, most of the forms of deterioration which wine undergoes have been recognised as due to biological action. Thus the Kahmigwerden, the Essigstich, and the Milchsäurestich of German writers, the poux and the graisse of French œnologists, are ascribed to the undesirable activity of various bacteria, moulds, and yeasts. Sourness, for example, is often due to acetic acid produced by the ferment Mycoderma aceti from the alcohol of the wine; whilst another mycoderm (M. vini) is believed to produce faulty wine by attacking the cream of tartar and albuminous extractive matters.