A clayey rock created by the weathering of volcanic ash. It got its name after the first discovery at Fort Benton in the US state of Wyoming. The mineral, also known as alumina, consists of calcium, sodium and aluminum silicates. It has a high Adsorption capacity (Accumulation of gases or dissolved substances) and good swellability and thus increase in volume. In viticulture, low-swellable calcium bentonites or medium-swellable mixed bentonites (calcium and sodium) are used for different fining respectively. Stabilization techniques like protein or heat stabilization used. The thermolabile protein away. Untreated wines can become cloudy at temperatures from 17 to 20 ° C. Treatment can be in grape or done in wine.
Early treatment results in faster must clarification by better sedimentation in the degumming, less tendency to brown, and a quieter and foam-free fermentation, The result is more pure wines. A possible disadvantage of early treatment is a reduction in nutrients (amino acids). If used too late, too color and flavorings be adsorbed. With wine, one can Bentotest the amount of thermolabile protein and the resulting required amount of bentonite are determined. Pure calcium bentonite also makes it light deacidification reached. In the Sparkling wine production Bentonite is used in the remuage used as a vibrating aid. It also serves as an inert (carrier) when using toxic silver chloride, See also other fining techniques below beautiful as well as a comprehensive list of all vinification measures under winemaking,