Campden Tablets – What Are They?

Campden Tablets are a sulphur-based compound, made of sodium or potassium metabisulphite.  Most frequently they are potassium metabisulphite.  Their use is to add sulphites to a solution kill undesirable microbes, stabilise, prevent oxidation and/or to remove chlorine.

One of the most commonly used ingredients in home wine making are Campden Tablets. You will find them in almost any of the wine making recipes you will use; talked about in almost any of the wine making books you will read; and called into action by just about any of the homemade wine instructions you will follow.

What Do Campden Tablets Do?

The original reason Campden Tablets were used, in wine making, was to keep the wine from spoiling after it had been bottled.  By adding these tablets at bottling time, you could virtually eliminate any chance of wine falling victim to mould, bacteria and other foreign enemies.

Since their introduction, Campden Tablets have also become routinely used for sterilizing the juice prior to fermentation.  By adding Campden Tablets a day before adding your wine yeast, you can start your fermentation with a ‘clean slate’, so to speak.  All the unwanted micro-organisms will be gone.  Wild yeast and other bacteria.

Some home winemakers also use Campden Tablets with water to create a sanitizing solution. This solution will safely sanitize fermenters, airlocks, stirring spoons, hoses and all pieces of equipment that may come into contact with the wine ‘must’.

How Are Campden Tablets Used?

Their use is fairly straight-forward. You add one tablet to each gallon of wine must 24 hours prior to adding the wine yeast and before the fermentation.  Then, should you wish to, you add one tablet per gallon just before bottling.

The Campden Tablets must first be crushed and dissolved in a small amount of the wine or water. This mix is then stirred thoroughly into the rest of the batch.

You can use the Campden Tablets to create a sanitizing solution by crushing up 4 tablets into a litre of water.  This can be used as a sanitizing rinse, or you can pour it into a fermentation container and allow the fumes to sanitize in entirety.

What Campden Tablets Don’t Do?

Many beginner winemakers believe that Campden Tablets are a ‘magic pill’ of sorts.  One that can instantaneously stop a wine fermentation dead in its tracks.  While it is true that Campden Tablets can bring a fermentation to a stop for a period of time.  It is also true that these fermentations will usually gather themselves back up and eventually overcome the effects of the tablets.  The result is a continued fermentation – sometimes after the wine has been bottled.

The truth is, Campden Tablets are not designed to stop a fermentation and never have been.  There is really no ingredient that can be safely used by itself to assuredly stop a fermentation.

Chris Marshall – brewathome.shop (Last Updated: 7th November, 2022)