How Do You Stabilise Wine? Campden Tablets and Potassium Sorbate Explained
Quick answer: To stabilise a finished wine, wait until fermentation has completely stopped and the wine has cleared. Then add 1 crushed Campden tablet and 1g (about ½ teaspoon) of potassium sorbate per gallon (4.5 litres). The sorbate stops yeast multiplying and the Campden protects against oxidation and bacteria. Sorbate won't stop a fermentation that's still going, so always confirm it has finished with a hydrometer first.
Stabilising is what stops a finished wine starting to ferment again in the bottle. It matters most if you want to sweeten your wine. It relies on two cheap additives that do different jobs, and they work best together.
What each one does
| Campden tablets | Potassium sorbate | |
|---|---|---|
| Active ingredient | Sodium metabisulphite (releases sulphite, SO2) | Potassium sorbate (E202) |
| Job | Protects against oxidation and spoilage bacteria. Also sterilises fruit must | Stops yeast reproducing, which prevents refermentation |
| Dose | 1 tablet per gallon (4.5 litres), crushed and dissolved | 1g (about ½ teaspoon) per gallon |
| When | 24 hours before adding yeast to a must, and again at racking or bottling | Only after fermentation has finished |
Using Campden tablets at the start
For fruit and country wines, add 1 crushed Campden tablet per gallon to the must. Cover it loosely and wait 24 hours before adding the yeast. If you add yeast before then, the sulphite slows the fermentation badly.
How to stabilise a finished wine
- Confirm fermentation has finished. Your hydrometer should give the same reading two or three days in a row.
- Rack the wine off its sediment into a clean, sanitised vessel.
- Add 1 crushed Campden tablet per gallon, dissolved in a little of the wine.
- Add 1g (about ½ teaspoon) of potassium sorbate per gallon and stir well.
- Clear the wine with finings if it needs it. Kit finings usually go in after stabilising.
- Sweeten if you want to, then bottle.
Common mistakes
- Adding sorbate to stop an active fermentation. It won't work. Sorbate stops yeast multiplying, but it doesn't kill the yeast that's already working. Let fermentation finish first.
- Using sorbate without Campden. Always use them together. Sorbate on its own leaves the wine unprotected against oxidation and bacteria.
- Using sorbate in beer or anything you want to carbonate in the bottle. It stops the priming sugar fermenting, so the bottles stay flat.
- Using too much Campden. Keep to no more than about 3 tablets per gallon over the wine's whole life.
What about wine kits?
Most wine kits come with their own stabiliser sachet, so follow the kit instructions. The doses above are for country wines, fruit wines and meads made from scratch, or for adding extra protection to a kit wine you plan to sweeten. If you prefer a labelled product, our Fermentation Stopper (Wine Stabiliser) is potassium sorbate.
For more detail, see our guides to potassium sorbate and Campden tablets, or browse treatments, nutrients and enzymes.
Frequently asked questions
How many Campden tablets per gallon?
One crushed tablet per gallon (4.5 litres). Use it at the start of a fruit wine, and again at racking or bottling.
How long after adding a Campden tablet can I add yeast?
Wait 24 hours. If you add the yeast sooner, the sulphite will badly slow the fermentation.
How much potassium sorbate per gallon of wine?
1g, which is about half a level teaspoon, per gallon (4.5 litres). Add it once fermentation has finished, together with a crushed Campden tablet.
Will potassium sorbate stop an active fermentation?
No. It stops yeast reproducing but doesn't kill the yeast that's already active. Wait until fermentation has completely finished.
Do I need to stabilise wine before back-sweetening?
Yes. Without sorbate and Campden, the added sugar can restart fermentation in the bottle. That can cause fizzy wine or burst bottles.