Skip to content
Click The Brewbitz Logo to go to the Brewbitz Homebrew Home PageClick The Brewbitz Logo to go to the Brewbitz Homebrew Home Page

When to add campden tablets when making wine

There are 3 stages in wine making where you need to add campden tablets. Read our blog to find out the 3 stages in wine making that you need to...

When to add campden tablets

 

There are 3 times when you need to add campden tablets to you wine making.

 

The First Time to add campden tablets is at the beginning of wine making. Lets say you have just added your fruit to your bucket and have poured boiling water over it. Once it has cooled to 20°C, add 1 crushed campden tablet per 4.5 litres of wine must, then stir. You can also add your pectolase at this stage.

 

Campden tablets do 3 things at this stage,

 

A - they stop bacteria and yeast from multiplying. They dont actually kill them.

 

B - they prevent your wine must and fruit from oxidising. They suck up all the spare oxygen that is dissolved in the water and fruit juices.

 

C - they create sulphur dioxide. Due to the reaction in B, they create a gas that’s heavier than air, so sits on top of the wine must. If you breathe in sulphur dioxide as soon as it hits your mucus in your nostrils or your throat, or your lungs, it turns in sulphuric acid. It will make you cough. But this is what creates a protective barrier and will stop things like wine fly from getting to your wine must in introducing an infection.

 

After 24 hours the effects start to diminish but that’s when you add your yeast. You add enough to start a fermentation. Quickly the yeast you have added will create some alcohol. This is then enough to kill any bacteria that might have been present. The yeast you have added will become the dominant yeast in your must and will do all the hard work of converting sugars to alcohol, but the wild yeast will come back from hibernation and will do their funky things in the background.

 

 

The second time you need to add campden tablets is when the fermentation is complete and you are wanting the wine to clear.  When the wine has finished fermenting and the sg is below 1.000 it’s best to add a campden tablet to help knock out the remaining yeast. Adding the campden tablet at this stage makes any remaining yeast more susceptible to the alcohol, which will help to kill them.   

 

So rack the wine off the sediment into a clean sterilised demijohn, add 1 crushed campden tablet per 4.5litres (1gallon). Pop in the airlock and transfer somewhere cool to clear.

 

The third time to add campden tablets is when the wine is clear and ready to bottle. Adding them at this stage helps to prevent oxidisation, helps to prevent the vinegar bacteria getting a grip on your alcoholic wine and turning it to vinegar, and together this helps keep your wine fresh in the bottle. 
If you are planning to lay down your bottles for a year or two, especially if you are ageing red wines for many years, adding a campden tablet at the bottling stage, really helps to preserve the flavours, colour and body.

 

How to use a campden Tablet

You need to crush the campden tablet into a powder before you can use it.  This is very easy, just place the campden tablet on a desert spoon, then take another spoon and using the back of the second spoon, twist and crush the 2 spoons together and the tablet will crush.  Watch our YouTube video on The Easy Way To Crush A Campden Tablet

4 comments on When to add campden tablets when making wine
  • Davin - Brewbitz
    Davin - BrewbitzMarch 25, 2026

    Hi Geoffrey. You need to check the hydrometer reading over 3 consecutive days and if it is changing, then it’s not the right time to add the campden tablet. Give it time, it will finish and start to clear. Campden Tablets are great when fermentation has finished and yeast activity is low. It can help subdue the remaining yeasts and then the alcohol will finish them off. But if there is still a lot of yeast activity, then some can continue to ferment. Sometimes you may see bubbles through the airlock, but this isnt necessarily a sign of fermentation. If you want to stop a fermentation, use Fermentation Stopper – Potassium Sorbate – https://www.brewbitz.com/products/fermentation-stopper-pottassium-sorbate-wine-stabiliser-30g – This takes 48 hours and will kill all yeast.
    Hope this helps

  • Davin - Brewbitz
    Davin - BrewbitzMarch 25, 2026

    Hi Gary – Check the hydrometer reading over the next 3 days. If it remains the same, it has likely finished fermenting, but what you are now seeing is trapped CO2 escaping. Hope this helps

  • Gary
    Gary March 25, 2026

    My hydrometer is 0.994 but airlock is still active but slow can I add Camden tablets though it’s slow

  • Geoffrey Taylor
    Geoffrey TaylorFebruary 09, 2026

    My wine had stopped fermenting and the sg was below 1,000 it was racked off and put back into a sterilised Demi john and and a campden tablet added by. It has now started to ferment again, however the other Demi John is doing nothing (just clearing nicely) is this normal.

Leave a comment

Your email address will not be published..


Adverts

On our blog pages, you will see some adverts. These help to supplement our work in writing these blogs, as they are viewed by many people around the world. As we are only able to ship the UK, these help us earn valuable income from people that use our website and information from overseas.

If the content of the advert interests you, then feel free to click it, otherwise, you can just ignore them. Many thanks and we appreciate your understanding.

Select options