I've had a lot of trouble finding a quick and easy answer to this question. Wine makers will add these chemical to wine after fermentation to prevent spoilage, and as an antioxidant. You can also add these two ingredients in mead, cider, wine, and beer to stop fermentation in order to hit a final gravity, or back sweeten.

Without the use of a SO2 meter, what is a good approximation of how much potassium metabisulfite/Potassium Sorbate I should add to stop fermentation?

Measurements in grams/gallon please..

3 Answers 3


One tablet in one gallon of must yields 150 ppm total sulfur dioxide.

Those instructions are on the bottle of Campden tablets, which are potassium metabisulfite.

Here's a source for Campden tablets.

It is common to use Campden tablets in wine, mead, and sometimes cider. It is less typical to use in beer, although it can be.

Potassium Sorbate also has instructions right on the bottle.

"Potassium sorbate, aka "stabilizer," prevents renewed fermentation in wine that is to be bottled and/or sweetened. Use 1/2 teaspoon per gallon."

Here is a source for Potassium sorbate.

It is my understanding that you use one or the other, either Campden or Potassium sorbate, not both.

Potassium sorbate and potassium metabisulfite accomplish different things, and can be used together to both stop fermentation and prevent renewed fermentation.

related question

Hope that helps.

  • 2
    You have to add both to stop and prevent fermentation. K-meta kills and the K-sorbate prevent the yeast from reproducing. When added, the gravity will still fall a few points while the process occurs. There is plenty of information out there. Here is one post. fermentarium.com/content/view/165/58 Both can absolutly be added to beer. Especially in beers with high amounts of fruit or honey. Or if you have a stuck fermention and require extreme measures, ie Champagne yeast. I have both chemicals in bulk powder form. I want to know how many grams per gallon to add.
    – Tim Weber
    Dec 23, 2009 at 1:59
  • 2
    As to your questions, the labels to the products I listed above also answer your questions: Potassium sorbate at 1/2 teaspoon per gallon. There is no good way to convert teaspoons to milligrams due to the unknown density of your potassium sorbate. For the potassium metabisulfite, Campden tablets are 550milligrams for 1 gallon, assuming what you have is the same.
    – TinCoyote
    Dec 23, 2009 at 5:14
  • The weight equivalents for volume measures of various wine-making additives is here: winemaking.jackkeller.net/measures.asp Nov 15, 2014 at 16:23
  • @TinCoyote maybe I'm interpreting your comments wrong, but you comment about the labels like everyone else has the same bottles as you; not everyone's KMeta and KSorbate bottles have instructions on them.
    – turboladen
    Nov 23, 2014 at 23:55
  • According to wikipedia: Campden tablets typically contain 0.44 g each of sodium metabisulfite (plus filler) and 10 of these are equivalent to one level teaspoon of sodium metabisulfite. One crushed Campden tablet per US gallon of must or wort contributes 67 ppm sulfur dioxide... en.wikipedia.org/wiki/Campden_tablet
    – Philippe
    Nov 3, 2015 at 13:02

I am assuming that you are making wine. For beer, neither sorbate nor SO2 have a place, since homebrew either creates carbonation from fermentation in the bottle or via CO2 injection in a keg, and usually there is no residual sugar to worry about for "re-fermentation" later in either case given timelines for deciding when to bottle/keg, meaning re-fermentation can be avoided without chemicals.

For wine, honestly, don't be in a hurry. The only thing to stop fermentation here is 1) there is no more sugar in the must for the yeast to "eat", or 2) you filter the yeast out (if you really are in a hurry --> but costs $$ for the pump and filters).

Sorbate will not stop fermentation forever, only for a "while" -- but may be enough until you drink everything, in which case the Web is full of doses you can attempt. But SO2 is intended mainly for controlling bacteria and is highly unreliable for "preventing yeast from multiplying" if you don't do residual sulfur tests.

Plus, "preventing yeast from multiplying" is not the same as preventing fermentation.

So neither sorbate nor SO2 are fool-proof against re-fermentation if there is a significant residual sugar left.

Either use a yeast that dies at your top-level alcohol requirement (Lalvin D47 and 71B stop at 14%), or use a good filter system, or build a mini-test-lab in the basement.


Short answer: none. It is a common misconception that metabisulphite stops fermentation. It doesn't. It is an oxygen scavenger and a bacterial inhibitor.

As already mentioned above you should use potassium sorbate to halt fermentation.

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