Fining and Fining Agents

By Bill Collings

Most winemakers employ fining agents before filtering, primarily for clarification purposes. However, fining serves additional functions including “colour, odour, flavour and stability.”

How Fining Agents Work

Common fining agents operate through electrical charge attraction. These include “bentonite(−), Sparkolloid(−), gelatine(+) and egg white(+), and silicon dioxide or kieselsol(−).” Others like carbon and PVPP work through adsorption rather than electrical charge.

Specific Fining Agents

Bentonite is widely favored due to ease of preparation and application. Prepare a 5% slurry in a blender and let it rest 24 hours before using at “4.5 cc per litre.” Excessive use risks stripping flavor and imparting earthy notes.

Gelatine addresses clarification and astringency reduction, typically paired with kieselsol. Use “0.02 to 0.04 grams per litre” or liquid versions at “0.66 cc per litre.”

Egg White suits red wines, reducing harsh tannins at “3 to 4 per twenty-five gallon barrel.” Mix with salt to create a smooth consistency without foam.

Kieselsol (silicon dioxide) reduces bitterness in white wines. The label recommends “2.2 cc per litre,” though “1.4 cc per litre seems to be effective.”

Carbon and PVPP remove oxidative odours and browning rather than clarify, used at “0.025 to 0.6 grams per litre” and “0.12 to 0.72 grams per litre” respectively.

Conduct lab tests before full-batch treatment and rack off sediment within two to three weeks to prevent degradation.