A clay-bearing rock that was created by the weathering of volcanic ash. It got its name after the first site at Fort Benton in the US state of Wyoming. The mineral, also referred to as clay, consists of calcium, sodium and aluminum silicates. It owns a high Adsorption capacity (Addition of gases or solutes) and a good swelling capacity and thus increase the volume. In viticulture low-swelling calcium bentonites or medium-swelling mixed bentonites (calcium and sodium) for various fining or. Stabilization techniques as protein or heat stabilization used. This is the thermolabile protein away. Untreated wines can form heat transfer even at temperatures of 17 to 20 ° C. The treatment can be in grape or in wine.
An early treatment results in a faster must clarification by a better discontinuation of Trubstoffe when degumming, less tanning tendency, as well as a calmer and foam-free fermentation, The result is purer wines. A possible disadvantage of an early treatment is a nutrient reduction (amino acids). When too late application can also color and flavorings be adsorbed. By the wine can by a Bentotest the amount of thermolabile protein and the resulting required amount of bentonite are determined. By pure calcium bentonite is also a light deacidification reached. In the Sparkling wine production Bentonite is used in the remuage used as Rüttelhilfe. In addition, it also serves as an inert (carrier) with the use of toxic silver chloride, See also other fining techniques below beautiful and a comprehensive list of all vinification measures under winemaking,