During the various stages of winemaking, yeast-derived products can also be used, which are: cell walls, cell membranes, inactive yeasts or yeast self-lysates. During fermentation, they are used to activate fermentation when alcohol levels are too high and fermentation too slow or difficult, while during the maturation phase, they are used to characterize wines. Depending on their properties, they can produce a more rounded flavor or reduce the astringency of certain very tannic wines, other products, with antioxidant power, rich in glutathione will avoid the browning of white wines or give a fresher flavor to acid wines, still others with high adsorbing and detoxifying power are suitable for correcting abnormal wine tastes.