Fining derives from the Latin finire, “to finish.” To fine a wine, the winemaker stirs a fining agent into a vat. This material attaches to microscopic particles in solution, an action called flocculation. This mass then precipitates to the bottom of the tank.
Fining removes protein, long-chain tannin, pigment, phenolics, and other soluble materials that could later cloud the wine. Most commercial white wines and many reds are fined one or more times.
Fining is not the exclusive realm of winemaking; it’s also used in food processing, for example to make clear consommé. A chef stirs a slurry of egg white into cold stock, then gradually raises the temperature of the pot. Particles suspended in the stock stick to the egg white, forming a mass that can later be removed.
Fining agents
There are two main sources of fining agent, organic and inorganic. The organic substances are proteinaceous, historically made from animal products, but today non-animal substitutes are available. Inorganic substances include clay, carbon, and synthetics.
The following fining agents, listed with their source material, are broadly permitted:
Albumen — animal (egg white)
Casein, or potassium caseinate — animal (milk protein)
Isinglass — animal (fish swim bladder)
Gelatin — animal byproducts
Chitosan — fungus (Aspergillus niger)
Yeast protein extract — fungus (Saccharomyces)
Alginate — algae (brown seaweed)
Pea protein — plant
Potato protein — plant
Activated carbon — plant-derived charcoal (wood, coconut shell)
Bentonite clay, or sodium bentonite — mineral
Kaolin clay — mineral
Silica gel, colloidal silicon dioxide — mineral-derived, synthesized
Polyvinylpolypyrrolidone (PVPP) — synthesized polymer
Fining agents don’t remain in the wine and are therefore considered processing aids, not ingredients.
Fining pluses and minuses
Fining removes the precursors that can later cloud the wine. It is helpful for fixing the color in white wine, removing particles that can cause browning. It can similarly reduce color in a red.
Fining also removes some tannin, which smooths the texture of red wine. Even winemakers who forgo other manipulations may use a fining agent to create this silkiness.
Fining can compromise a wine’s delicate aromatics, so winemakers will often run trials to determine the absolute minimum fining agent to attain a balanced result.
Natural winemakers in particular regard the tactic as an unnecessary manipulation, as wine can be clarified simply by racking, or gently moving it off its sediment. This step may need to be repeated and can introduce oxidative faults if mishandled, but naturally clear wine is possible, if labor intensive.
Talking about Fining
You’ll rarely find a winery touting its fining process, since it may raise more questions than it answers. More often you’ll see a wine labeled un-fined, which signifies the wine was clarified and stabilized without a processing aid.
Animal-derived fining agents are a concern for vegetarians and vegans, so wineries that don’t fine, or that use only inorganic, plant, or fungal agents, may declare their wine “vegan friendly.”
Winemakers who avoid fining will likely also avoid filtration, a separate process in which the wine is passed through a membrane to remove additional particles and microbes. Such wines will be described as un-fined and unfiltered.
Further reading
Images of the Atelier des Découvertes in the Cité du Vin, Bordeaux ©2026 Meg Maker