Alternatives to Bentonite 1995

Wine hazes are considered to be a visual sensory defect. Bentonite works extremely well at removing most species of proteins rendering wine protein stable. We do not have an equally reliable method for the removal of polysaccharide material which can also lead to a haze due to insolubility in ethanol. Bentonite is not specific and can strip wines of important flavor and aroma characters. In addition to this quality issue, bentonite use also generates solid waste and counties in California are seeking ways to minimize the volume of solid wastes produced. An alternative to bentonite that would result in protein stability without generating massive quantities of waste, adding any sensory attribute, or stripping wine characters is desirable. We are exploring the ability of the Saccharomyces protease, Protease A, to function in degrading wine proteins and elimination of protein hazes. We are also conducting a detailed compositional analysis of wine hazes to define the wine components that trigger haze formation. Once more is understood about the kinetics of haze formation, other alternatives to bentonite may become apparent. Our final goal is to characterize the haze material that is not protein and also to define the role of polysaccharide in the generation of haze. This year we will be including analysis of recurring haze problems being experienced by white Zinfandel producers.