Isolement et identification des levures

The fermentation of the grape must is ensured by the yeasts which are found on the skin of the grapes, on the stems, and also, by those which invade the harvesting and vinification equipment as soon as the harvest has begun. The appearance of fermentation of grape must is ensured by the yeasts which are found on the skin of the grapes, on the stems, and also, by those which invade the harvesting and winemaking equipment as soon as the harvest has begun. The appearance of signs of fermentation is spontaneous. Fermentation is rapid in most cases, if it becomes too violent and the temperature rises dangerously, it must be "channeled" and calmed. Accidents can happen; fermentation stops leaving unfermented sugars that can be attacked by other microorganisms, growth of yeasts forming substances harmful to quality; subsequently, it is a question of obtaining the stability of the wine, in particular, avoiding the refermentation of sweet wines. The study of these problems requires a preliminary study, that of the yeasts responsible for the alcoholic fermentation of grape juice, which can only be done on pure cultures, isolated beforehand using carefully taken samples. fermentation is spontaneous. Fermentation is rapid in most cases, if it becomes too violent and the temperature rises dangerously, it must be "channeled" and calmed. Accidents can happen; fermentation stops leaving unfermented sugars that can be attacked by other microorganisms, growth of yeasts forming substances harmful to quality; subsequently, it is a question of obtaining the stability of the wine, in particular, avoiding the refermentation of sweet wines. The study of these problems requires a preliminary study, that of the yeasts responsible for the alcoholic fermentation of grape juice, which can only be done on pure cultures, isolated beforehand using carefully taken samples.