Choosing A Fining Agent For Your Wine

Fining is one of the few winemaking decisions where the wrong product doesn’t announce itself. A poor choice rarely ruins a wine outright, it quietly removes a little more aroma than you intended, or leaves a haze that only shows up months after bottling. The cost is real but invisible at the time you make the call.

This guide works through the decision the way the vintage does, from juice arriving at the winery through to a wine being prepared for bottling. Along the way it covers what each type of fining agent is actually made of, because composition is what determines where a product works best.

what you’re actually removing

Fining is a broad word for several unrelated jobs:

• Suspended solids in freshly pressed juice, which need to come out fast so fermentation starts clean.
• Oxidisable phenolics: The catechins and other compounds that drive browning, bitterness and premature ageing.
• Pathogenesis related proteins, mainly thaumatin-like proteins and chitinases, which cause protein haze in the bottle.
• Metals such as copper and iron, which catalyse oxidation.
• Taint compounds like smoke, mould and vegetal characters.

No single product does all of these. Choosing well means being specific about which one you’re solving for.

composition determines application

Most modern fining agents are built from a small number of active materials. Knowing what each one does makes the product range much easier to navigate.

Chitosan is a positively charged biopolymer derived from fungal sources. That positive charge is the whole point: it neutralises the negative charge on suspended particles and oxidisable phenolics, causing them to flocculate. It works very fast, fungal sources are non-allergenic, and it’s active against oxidation as a free-radical scavenger. It is not a strong deproteinsier.

All Chitosan in the Winequip range is 100% fungal origin from Aspergillus niger, in compliance with the OIV International Oenological Codex. This is worth confirming with any supplier, as shellfish-derived chitosan is still common and carries an allergen declaration.

Plant proteins, typically pea and potato, behave much like the animal proteins they replace. They bind and precipitate phenolic compoundsm reducing bitterness, astringency and browning potential. They’re gentler than gelatine, which means less risk of stripping, but also means dose rates matter more.

Yeast protein extracts are highly reactive with oxidisable phenolics and are particularly good at removing bitter and drying fractions without flattening the wine. They’re often blended rather than used alone.

Bentonite is a clay with a strong negative charge. It’s the only material on this list that reliably removes haze-forming proteins, and it also weighs down and compacts lees from other fining agents.

Activated carbon removes colour and taint compounds. It can be a blunt instrument and should be used after trials.

at the juice stage

Juice stage fining is where the biggest quality gains are available, because removing oxidisable material before fermentation prevents problems rather than correcting them.

flotation

Flotation clarifies juice quickly and with less aroma loss than extended cold settling, and it suits high-throughput vintages where tank space is short.

Qi’Up XC™ is a highly concentrated chitosan flotation aid for all wine varietals. Its very high positive surface charge drives rapid floccule formation, and it performs consistently regardless of juice turbidity or flotation technique. It’s a direct alternative to gelatine, with no allergen declaration required.

Bent’Up™ is used alongside a flotation aid to neutralise the electrical charge of the resulting floccules, tightening the cap and speeding clarification.

Qi’Fine™ combines chitosan with pea protein, which makes it more reactive with oxidisable compounds than chitosan alone. It works as both a fining and flotation aid, and it’s the stronger choice where the juice is already showing oxidative character or comes from marginal fruit. Available in both powder and an easy to use liquid form.

Acticarbone Eno™ is an inert vegetal charcoal for decolourising juice and staines white wines, formulated to leave the bouquet intact. A strong choice for rosé.

settling and oxidation control

Inofine V™ is an allergen-free plant protein designed to combat oxidation in juice and wine while contributing to clarification. It’s a useful default on white and rosé juice where you want oxidative protection without the phenolic stripping a heavier fining would cause. Suitable for use in flotation thanks to it’s high flocculating action, as well as post ferment to fine tune wines.

No[Ox]™ pairs chitosan with bentonite, so the antioxidant action and the sedimentation happen in a single addition. It is strong at eliminating iron and copper while preserving aromatic freshness. Also suitable for use on wines post ferment to erase organoleptic defects by eliminating bitterness and oxidative notes.

on wine, post fermentation

By this point the objective shifts from prevention to refinement – adjusting the phenolic profile, correcting faults and preparing the wine for stabilisation and filtration.

Fyneo™ is a top grade clarifier that drives rapid sedimentation while removing harsh and bitter end notes. Its strength is that it refines the finish without dulling aromatic intensity, which makes it well suited to whites and rosés where you want polish rather than correction.

The latest innovation from IOC, Unifyne™ blends yeast protein extracts, pea protein, chitosan and benonite. That breadth is the point: it’s a natural alternative to PVPP, covering phenolic reduction, oxidation protection and sedimentation in one product. Where you’d be otherwise stacking two or three additions, it’s usually the more economical route.

Both are allergen-free and contain no animal derived material.

correcting faults

Flavoclean™ is an activated vegetal charcoal for deodorising juice and wine, particularly effective against mould and vegetal taints caused by Brettanomyces and Botrytis.

Qi’Smoke™ combines chitosan with high quality carbon for the reduction and removal of smoke taint. Trial thoroughly: smoke affected parcels vary enormously, and the carbon component will take colour and aroma with it if overdosed.

Trap’Metals™ is a chitosan-based product for reducing copper and iron concentrations in juice and wine. Note – Trap’Metals contains PVI/PVP.

protein stability

Where protein stability is the objective, bentonite is your key tool.

Bentostab™ is a granulated activated sodium bentonite with high deproteinising power, developed for efficient clarification of musts and wines. It’s the ideal choice where protein removal is the priority.

Inobent™ is strong on protein stabilisation while being notably good at preserving primary and secondary aromas, which makes it the better option on aromatic whites and on base wines for sparkling.

Compact Due is a high quality activated bentonite that clarifies well and delivers better colloidal stability with tight, compact lees. Useful where wine recovery from lees is a concern.

trial first

No guide replaces a bench trial. Fining agents should be used at the lowest dose that achieves the objective. Every increment above that costs aroma, mouthfeel and colour.

A workable approach:

1. Run a wide-range trial first to bracket the effective dose, then a narrow one to refine it.
2. Always include an untreated control.
3. Replicate the finished wine exactly – if the wine will see other additions, they belong in the trial.
4. Where protein stability is the goal, confirm with a heat stability test after fining is complete.
5. Where a protein-based fining agent has been used on a white, re-test heat stability afterwards. Protein additions can themselves affect the result.

need a recommendation?

Our fining and flotation selection tool will point you to the right product in under a minute, or you can view our full range of IOC fining, flotation and stabilisation products.

For more specific advice, contact your local Winequip office. Our team are experts in these products and can advise on the right approach for your fruit.