Winegrowers Supplies  -  Bentonite

For protein stabilisation, fining and adsorption of undesirable substances in must (or wine).

The exact quantity to be added can be determined by a suitable test (such as the Erbsloh Oenotest); however, for simple preventative treatment 100 (to 150) grams per 100 litres should be used. Bentonite strips out flavour components from the wine, so only the minimum amount necessary should be used.

The bentonite granules should first be stirred well (with a stainless steel whisk) into a 5 fold quantity of water and allowed to soak and settle for 3 to 12 hours. Then pour off excess water and add the bentonite suspension to the must (or wine), rousing thoroughly (for 10 to 15 minutes) while the bentonite is being added; the protein is removed during this time. This length of rousing time is not necessary with must, as the fermentation will achieve the same result.

Pure sodium bentonite is also available, this is used particularly for Sparkling Wine. Warm water is necessary to prepare it. A smaller quantity is used (30 to 80 grams per 100 litres).

Bentonite is not usually added to red wines.

Calcium bentonite settles out more quickly than sodium bentonite does, but normally takes 6 to 8 days.

Bentonites are hygroscopic and need to be sealed from moisture and odours.