bentonite is a 'mixed oxide of aluminium and silicon, if added at the start of fermentation it helps to drive off the carbon dioxide produced, ensuring a rapid and smooth fermentation. It also fines the wine at the end and is especially effective at removing proteins, which can come either from the must or from the yeast. Bentonite needs to be dispersed as a fine slurry before adding to the wine.
Suitable for vegetarians.