Estudi de l'evolució del comportament escumant i de la fracció col·loidal del cava durant la seva elaboració; efecte de diferents tractaments

Resumo

The foaming ability of a sparkling wine is conditioned by different tensioactive products and their capacity to stabilise or not the bubbles gas-liquid interphase. The present study proves the positive effect of wine colloids on foaming expression as well as the negative effects of some fatty acids. During sparkling wine making, any change that may modify the chemical composition will change the foaming ability. We have studied the effect of different compounds used for wine fining and tirage on the foam and their relation to changes in wine colloid concentration. Facing the broad diversity of these products available to wine maker, our goal is to provide decision tools for its election. Some new additives are proposed for foam improvement (inactivated yeasts and colloids coming from grape skin or fermented synthetic medium). As for the prise de mousse (second alcoholic fermentation), the yeast strain is an additional parameter to be considered. Finally, the changes during ageing in contact with yeast lees affect both the colloid composition of wine, and thus the foaming ability.