Comparing Seven Bentonite Products for Efficacy, Compaction, Cost and Sensory Effects

Winery: King Family Vineyards

Contact: Matthieu Finot

Grape Variety: Viognier  

Objective: The purpose of this trial was to determine the effective dosage, compaction rate/volume loss and sensory effects of different bentonite products when used on Virginia Viognier. 

Description: After completion of fermentation, a barrel fermented Viognier was used to test seven bentonite products. Products were sourced from several different companies (Scott Labs, Enartis, AEB, Vason) for inclusion in the trial. The trial included sodium, calcium and activated bentonites. For each, a bench trial of bentonite dose was performed to determine the effective dose needed to achieve protein stability (defined as a change in NTU less than 2.0). Carboxymethyl cellulose (CMC) stability at this rate will also be determined, as this is a motivating factor for bentonite usage. Percent loss at the effective rate was calculated using the amount of sediment produced as observed in clear plastic tubes with side gradations. From this trial, four bentonites were chosen to treat a keg of wine for sensory analysis. Each keg was treated with a different bentonite product at its effective dose rate and allowed to settle according to manufacturer’s instructions. After settling, wine was racked off bentonite lees and sent for ester analysis. These wines were also tasted blind by a panel of winemakers in two separate sensory sessions with sensory descriptors, difference from control and preference tested.

Lot Description: 

Lot 1: MasterVin Compact (BSG) 

Lot 2: Bentogran (AEB) 

Lot 3: PluxCompact (Enartis) 

Lot 4: KWK (aka Volclay)(Brenntag)

Lot 5: Control (no bentonite)

Conclusions: Efficacy of bentonite products varied widely, with KWK having the lowest dose to achieve stability (32.5 g/hL) while Enartis Pluxcompact requiring the highest dose (96.5 g/hL). Despite the high rate of addition, Pluxcompact had the lowest loss at its effective rate (1.8 percent), due to efficient compaction of lees, while others (Plusgran, Bentogran, Pluxbenton) had more than 10 percent volume loss. Analysis of esters showed surprisingly small differences relative to control, with the largest differences (above 10 percent) shown in wines treated with Pluxcompact and KWK. Sensory analysis results are pending, and will be available within the next month.