Ask Wine Wizard

Rules Of Fining

TroubleShooting

Kieran Ridley — Perth, Australia asks,
Q

This is my first time using a fining agent in my wine. after you use a fining agent will there be sediment again at the bottom of the fermenter? Do you need to filter wine after using a fining agent? Thanks for your help.

A
Indeed, after using most fining agents there will be a layer of sediment generated and you’ll need to rack the wine off of it accordingly. Fining agents, by definition, are introduced into a wine to interact with whichever of the wine compounds you are trying to mitigate or reduce. For instance, bentonite is a natural clay used for centuries as a fining agent. The clay is dissolved in water then is mixed into the wine as a slurry, where it combines with proteins, forms larger particles and “pulls” the proteins out of solution before settling by gravity as a layer of sediment. Sometimes proteins (egg whites are an ancient and still-effective example) are added in order to react with excess tannins, forming larger particles that fall to the bottom of barrels, kegs, or carboys. If you can get a good, compact, settled layer it’s not necessary to filter a wine, unless you want to. Be sure to read package instructions carefully and use the correct doses — with fining agents the danger is often over fining. Too much bentonite can
Response by Alison Crowe.