Bentonite fining

Duncan, B. (1992). Varietal differences in white grape protein Implications for bentonite fining. Aus. New Zealand Wine Ind.. 7,189-193. 

Hsu, J. C. and Heatherbell, D. A. (1987). Heat-unstable proteins in wine. I. Characterization and removal by bentonite fining and heat treatment. Am. J. Enol. Vitic. 38,11-16. 

Clarification and Stabilization Combinations. Wine clarification may be combined with a stabilization step to minimize handling of the wine. This type of clarification, timing, and sequence vary from winery to winery. Some options used are, after fermentation, rack the wine off yeast lees, bentonite fine for heat stability and chill for cold stability, then diatomaceous earth filter to remove remaining yeast, bentonite, and tartrate crystals after fermentation, centrifuge the wine to remove yeast solids, then chill and add bentonite, and filter to remove yeast and add bentonite, chill, then pad filter to remove bitartrates and protein. 

Main, G.L., Morris, J.R. (1994). Color of Seyval blanc juice and wine as affected by juice fining and bentonite fining during fermentation. Am. J. Enol. Vitic., 45, 417 22. 

Zoecklein B.W. (1988b). Bentonite fining of juice and wine. Department of Horticulture Virginia Polytechnic Institute State University, Publication 463-014. 

As well as the perceived but questionable adverse sensory effects of bentonite fining,... 

The in-line dosing paradigm exploits the observation that protein adsorption by bentonite occurs rapidly - within several minutes (Blade and Boulton 1988 Muh-lack et al. 2006). Furthermore, if combined with centrifugation, the bentonite and wine can be separated and the bentonite lees are simultaneously compacted to reduce value losses. In-line dosing methods for bentonite fining are already used... 

Muhlack, R., Nordestgaard, S., Waters, E.J., O Neill, B.K., Lim, A., Colby, C.B. (2006). In-line dosing for bentonite fining of wine or juice contact time, clarification, product recovery sensory effects. Aust. J. Grape Wine Res., 12, 221-234... 

BENTONITE FINING. Bentonite fining is primarily used to stabilize fruit juices against protein hazes. Bentonites are swelling clays. They have a... 

The freshly pressed juice is treated with hentonite (see section on Bentonite fining] and left to stand for 6—8 h. During this period, coarse particles and the hentonite are precipitated. Bottling and pasteurization then take place. The enzymes can break down pectin during the period while the juice is left to stand. This can lead to partial clarification of the juice in the hottle. 

Chardonnay (Figure 3). The binding of y-decalactone on bentonite increases of 6 fold in the presence of monosaccharides (model must and must of Chardonnay) compared to the control. Therefore the loss of aroma compounds caused by bentonite fining is higher in must than in wine. However weak effects on the behaviour of the flavor of wine were suggested. Indeed many of the aroma compounds in wine are produced during the alcoholic fermentation. Therefore these interactions may have an important effect on the flavor properties of the finished wine. 

Methods which reduce the undesirable effects of polyphenoloxW ases include pressing, centrifuging or settling musts, bentonite fining and thermal treatment (70°C for 3 min). 

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