During the winemaking it is known that the browning phenomenon has an enzymatic origin, the tyrosinase and peroxydase being the main oxidative enzymes. The laccase is mainly accumulated in the mouldy (botrytized) berries and only a small quantity is soluble in the must. It is little affected during the alcoholic fermentation and it is more stable in wine. The wines obtained from different harvests, especially from white grapes, are unstable, very susceptible to oxidative browning. The more intense cassation of the must and wine is when the mould and rot of the grapes are present. The aim of this study was to analyse the initial oxidative activity in the healthy grapes and mouldy ones with different degrees of contamination with the noble mould Botryotinia fuckeliana, from the fresh must, the must during the alcoholic fermentation and from the young wine after which the experimental variants were made. At the same time, it was studied the oxidative cassation of the wines obtained by processing healthy and mouldy grapes.