Wine Tannin Addition Calculator
Calculate how much powdered tannin to add to your wine.
Get the correct dose in grams per litre for structure, mouthfeel, and preservation.
What tannins actually do in wine
Tannins are polyphenols extracted from grape skins, seeds, stems, and oak. They bind to proteins (including the proteins on your tongue), which is why a young Cabernet feels astringent. Tannins also bind oxygen, stabilise colour in reds, and slow microbial spoilage. A wine with too little tannin tastes flabby and oxidises fast; with too much tannin, it tastes drying and unfinished. Hitting the middle is one of the trickier parts of red winemaking.
Types of commercial enological tannins
| Type | Source | Best use |
|---|---|---|
| Quebracho | South American hardwood | Structure, deep colour stabilisation in reds |
| Grape (skin-derived) | Wine grape pomace | Mid-fermentation to reinforce native tannin |
| Grape seed | Wine grape seeds | Strong bitterness; small doses for backbone |
| Chestnut / oak | European oak heartwood | Antioxidant, light astringency, oak character |
| Gallnut (tannic acid) | Oak galls | High purity for fining trials, very astringent |
The label on a tannin product tells you the source and the recommended dose range. Always read the manufacturer’s recommendations first — these ranges are conservative, but they save you from common mistakes.
Dose ranges by purpose (g/L)
| Purpose | Red wine | White / rosé |
|---|---|---|
| Structure and body | 0.10 to 0.25 | 0.05 to 0.15 |
| Antioxidant / preservation | 0.05 to 0.10 | 0.05 to 0.10 |
| Protein fining (for clarification) | 0.15 to 0.30 | 0.10 to 0.20 |
| Mouthfeel correction | 0.10 to 0.20 | 0.05 to 0.15 |
For a 23 L batch needing structure at 0.15 g/L: 23 × 0.15 = 3.45 g of tannin total. Dissolve in a small portion (200 mL) of wine first, then pour back into the bulk and stir gently.
When to add tannin during winemaking
- Crush — for grape-derived tannins to reinforce skin extraction
- Mid-fermentation — for structure tannins; the fermenting wine integrates them best
- Post-fermentation, pre-MLF — for finishing tannins, mouthfeel adjustment
- Pre-bottling — only if absolutely necessary; tannins added late often taste “added”
- Never to a wine already past peak — old wine cannot integrate new tannin
Bench trials — the most important step
Make 100 mL samples at 0.5x, 1x, 1.5x, and 2x the recommended dose. Wait 24 hours. Taste blind alongside the untreated control. The right dose is the one that you can’t taste as “added” but that improves balance — usually less than you think on the first try.
What over-tannining looks like
The wine tastes drying, bitter, and “stripped.” Mouthfeel goes thin instead of fuller. Once over-tannined, the wine often needs months of fining (with egg whites, gelatin, or PVPP) to recover, and rarely returns to its original character. When in doubt, dose conservatively and add more later.
Tannin will not save a bad wine
A wine with structural problems (low alcohol, high VA, bacterial spoilage) cannot be fixed by tannin. Tannin enhances good wine. Use it where the underlying wine is sound but lacks definition.