The addition of bentonite at different stages of white winemaking and its effect on protein stability

摘要

PROTEIN HAZE IS one of the key instabilities in white wine production. Grape proteins in wine can slowly denature and aggregate together into insoluble protein aggregates that make the wine appear hazy and, eventually, form unattractive sediments. Such wines are not saleable and, therefore, this protein 'instability' needs to be prevented. The common practice in all winemaking countries is to remove the proteins before bottling through adsorption onto bentonite. Bentonite is an effective treatment, but its application has some drawbacks, such as wine volume loss and disposal costs, as well as perceived effects on wine flavour and quality (AWRI publication #858). Hence, winemakers aim to use the minimum amount of bentonite for wine quality, cost andenvironmental reasons.