WINETECH Technical Yearbook 2019

While bentonite in its various guises might be one of the most widely used fining agents to remedy protein haze in white and rosé wines, it certainly is not the most perfect one. Numerous fining agents are available to the winemaker and the choice to use bentonite, and subsequently when to use it, will depend on various expected oenological outcomes. INTRODUCTION Generally speaking, oenological fining agents are used for the clarification and

stabilisation of wine by using compounds that flocculate, precipitate or react with the undesirable compounds in must or wine. The prevalence of heat unstable proteins in grape must makes the use of a fining agent, such as bentonite, necessary to remove them in order to prevent protein haze formation after bottling. These proteins mainly include the grape pathogenesis- related proteins, namely thaumatin-like proteins and chitinases. Bentonite fining can, however, have a negative effect on wine

BERNARD MOCKE: Private consultant KEYWORDS: Bentonite, fining agent, protein haze. OCTOBER 2019 FOCUS ON BENTONITE