Extraction of colour during fermentation of pinot noir wines and its stability on ageing

Abstract

The characteristics of the major pigments in red wines are discussed and the results of an experiment to stabilise the peak of colour extraction which occurs during fermentation are presented.

It was found that the peak which occurs early during the fermentation is due to the formation of anthocyanin aggregates and that this could be stabilised by the addition of a solution of commercial grape tannin.

This resulted in aged wines which were pressed at 43 hours after innoculation having similar colour densities to those wines fermented to dryness in the presence of the grape skins.

Treated wines showed increases in the amount of polymerised anthocyanin present at fifteen months despite an increase in the amount of polymerised colouring material deposited during this time.