GWH Blog

Using Bentonite Fining to Achieve Protein Stability in Wine


Clarity, or the absence of haze, is a key factor in the appearance of wine, contributing significantly to its commercial value. High temperatures, encountered during transportation or in poor storage conditions, can induce the denaturation of proteins, which then form a suspended haze in a bottle of wine and degrade its value. Bentonite can be used to treat protein instability, acting as a fining agent to pull proteins out of solution before they are bottled.

As with many fining agents, bentonite can remove other components that are important to a wine’s sensory properties. Because of this, benchtop trials are encouraged to ensure protein stability in wine without stripping too much of its aromatic compounds through the addition of an appropriate concentration of bentonite. Here at Gravity Analytical Laboratories, turbidity is measured via nephelometer before and after heat exposure to wines treated with varying concentrations of bentonite. If a difference in turbidity greater than 2 NTU is seen before and after heat, proteins are unstable, and a higher bentonite treatment will be required for proper stabilization.

For more information about bentonite and its use for haze prevention, join us at Gravity Analytical Laboratories as we walk through bentonite fining, our latest benchtop trial offering. If you would like to receive updates and emails with new educational posts, join our mailing list at the bottom of this page.