Anti-Ox®: what an oak tannin does against oxygen
An antioxidant that works in the wine, not a product for preserving empty barrels. The difference matters, and that is where we start.
Sulfur dioxide is still everyone's reference point in the cellar, and the requests that reach us almost never aim to eliminate it. They aim to use less of it, for reasons of labeling, market or taste. Oak tannins have a part to play in that story, but a precise part, and a narrower one than what you sometimes read.
What does a tannin do against dissolved oxygen?
Ellagitannins, the main tannic compounds in oak, oxidize easily. Put into a wine, they compete with the wine compounds that oxygen would damage first: the fragile aromas, part of the coloring matter. The tannin takes on a share of the dissolved oxygen in their place, and it also helps stabilize the color.
This is ordinary chemistry, not a shield. The amount of oxygen a tannin can take on is finite, and it depends on the dose, the pH, the temperature and what the wine already contains. We know how to observe the effect in our trials, but we do not know how to convert it into a single value that would hold true for your cuvée.
Does it replace sulfur?
No, and we need to be clear about that. SO2 does at least three things in a wine: it takes up oxygen, it binds carbonyl compounds, and it hinders some micro organisms. An oak tannin acts only on the first of those. It has no antimicrobial action, and a wine protected by tannin alone is still exposed on the microbiological side.
What we hear is that some winemakers reduce their SO2 additions by relying on an oak tannin. We have no consolidated figure to publish on the size of that reduction. The protocols, the vintages and the cellar conditions are too different from one estate to another for an average to mean anything. We would rather put forward nothing than put forward a percentage you would not find again at your place.
Do not confuse it with BARREL-PROTECT®
Both products are based on oak tannins, and that is the only thing they have in common. The confusion comes up often enough that we address it here.
| Product | Where it works | Reference figure |
|---|---|---|
| Anti-Ox® | In the wine, on dissolved oxygen | Dose to be set by trial, there is no single value |
| BARREL-PROTECT® | In the empty barrel, between two wines | About 4 months of protection, in place of the sulfur wick |
| Our tannins in liquid form | Dosed with a pipette, no maceration and no filtration | 20 % concentration, 1 L is equivalent to 200 g of powder |
In other words: Anti-Ox® goes into the wine, BARREL-PROTECT® goes into a barrel you have just emptied. Using one for the other's job makes no sense and will not give anything good.
How to try it without committing a tank
Drop by drop, on a few centiliters, with a range of doses. It is the fastest protocol we have for seeing what a tannin does to your wine, and it gives an answer within an hour: it is described here. Taste blind, and keep an untreated control.
The questions that come up most often about these products are gathered in our questions and answers. And if what you observe in your cellar contradicts what we write here, tell us. We would rather correct than defend.
Read next : BARREL-PROTECT®: protecting an empty barrel without sulfur · Brettanomyces in Barrels: How to Protect Your Wine Naturally