Carbonation of your beer

Carbonation of your beer

- Categories : Beer Tips

Carbonation is an essential criterion for appreciating a well brewed beer. Too little carbonation does not give the beer its refreshing touch, and a beer with too much carbonation can mask the flavours and lead to problems of exploding bottles. This last step in brewing is crucial to get the perfect beer, so let's see how you can get the perfect carbonation in your beer!

How does carbonation work?

This operation is performed when the yeasts have metabolised all of the fermentable sugars in the wort and sugar is added to the bottles to re-ferment and produce CO2. 

Closing the bottle filled with beer and sugar with a cap or clamp cap will force the CO2 produced during re-fermentation to remain in the bottle and dissolve in the beer, inducing carbonation. 

This process takes two weeks, and is ideally done at the same temperature as the wort fermentation in the fermenting bucket: between 18-25ºC for Ales and between 12-15ºC for Lagers. 

As you have seen, this carbonation process depends on two parameters: the pressure in the bottle and its temperature. Carbonation will be more intense at high pressure and low temperature. 

But it also depends on the fermentation temperature in the fermentation bucket: a low fermentation temperature will induce a higher carbonation of your beer before bottling. And that will mean it will need less sugar for bottle fermentation.

Which sugar can you use?

All sugars can be used for bottle fermentation, but they offer very different results. 

Corn sugar, or Dextrose, is the preferred sugar for bottle fermentation because it does not add any aroma to your beer and it is completely fermentable by the yeast. 

White sugar, or Sucrose, is also very popular because it can be found very easily in any supermarket. This sugar is quite neutral as well, and offers a better efficiency than dextrose.

But sugar in any other form can also be used: brown sugar, honey, non-fermented wort or malt extract for example. These more complex sugars offer much more heterogeneous results, have an impact on the taste of your beer, and can leave a residue in your beer. Therefore, we recommend using Dextrose or Sucrose when bottling. 

How can you add the sugar for carbonation?

Sugar can be added in different ways. The ideal is to add it in bottles, thus ensuring that each recipient will have the same carbonation. Remember that it is very important to add the sugar in a clean and sterilised bottle. And the accessory for adding the sugar, like our sugar dispenser for example, must also be clean and sterilised.

There are two ways to add the sugar in the bottles:

- The homebrewer way: using a dosing device to add the sugar into the sterilised bottle before filling it with beer. This technique is very simple and presents very little risk of contaminating the beer and making a mistake.

- The master brewer way: diluting the whole sugar you will need for your bottles in boiling water for 15 minutes to sterilise it, and distributing the liquid equally in each bottle with a pipette for example. To perform this technique, it is very important to know the amount of sugar you need for all the bottles, to measure the right volume of water to dilute the sugar without adding too much water in the bottles, and to be very careful with the handling and sterility of your tool.

We always recommend the homebrewer way because it is much easier, it is impossible to make a mistake, and it gives very good results.

Once the sugar is added in the bottles, you can transfer the beer and close them hermetically to rest for 2 weeks at the right temperature. 

How to calculate the amount of sugar to add in your bottles or barrels?

The most commonly used unit for determining the carbonation of beer is the "Dissolved CO2 volume". This unit works as follows: 1 volume of CO2 corresponds to 1 litre of CO2 dissolved in 1 litre of beer.

The desired carbonation depends on the beer style and traditions in each country: 

A Lager or a Pilsner is usually drank at very cold temperatures and with a lot of carbonation because these beers are appreciated when very refreshing. 

A Stout or a Porter has a fairly low carbonation to appreciate the body of these beers and their roasted flavours. 

Highly hopped beers have an intermediate carbonation to be refreshing while offering a fullness of hop flavours. 

And sour beers have a slightly higher carbonation to accentuate the refreshing sensation. 

To get an idea of the CO2 volumes for different beer styles, the following data might help you:

Beer Style --> CO2 Volume

British Style Ale --> 1,5 - 2,0

Porter, Stout --> 1,7 - 2,3

Belgian Ale --> 1,9 - 2,4

European Lager --> 2,2 - 2,7

American Ale & Lager --> 2,2 - 2,7

Lambic --> 2,4 - 3,8

Fruit Lambic --> 3,3 - 4,5

German Wheat Beer --> 3,3 - 4,5   

Now, let's see how to calculate the desired CO2 volume and the amount of sugar to be added during bottling. These volumes are calculated for Dextrose or Sucrose:

  • “Dissolved CO2 Volume” durante la fermentación en cubo fermentador (Dissolved Vol):

For this calculation, you will need to know the “Temperature of Fermentation” in your fermenter bucket (Temp Ferm).

Dissolved Vol = 1,7 - 0,059 x Temp Ferm + (0,00086 x Temp Ferm x Temp Ferm)

  • “Desired CO2 Volume” (Desired Vol) and “Total Sugar” to add in bottles or barrels (Total Sugar):

For this calculation, you will need to know the “Desired CO2 Volume” in your bottles and barrels. To do so, you can refer to the previous table. 

You will also need to know your “Total Beer Volume” in your fermenter bucket (Total Beer Vol).

Total Sugar = (Desired Vol – Dissolved Vol) x (Total Beer Vol) x 3,9

  • “Final Sugar Amount” to add in each bottle or barrel (Final Sugar):

This amount is determined according to the volume of your bottles  (25cl, 33cl, 50cl, 75cl, 1L) o your barrels (4,5L):

Final Sugar 25cl =0,25 x Total Sugar / Total Beer Vol

Final Sugar 33cl =0,33 x Total Sugar / Total Beer Vol

Final Sugar 50cl =0,5 x Total Sugar / Total Beer Vol

Final Sugar 75cl =0,75 x Total Sugar / Total Beer Vol 

Final Sugar 1L =1 x Total Sugar / Total Beer Vol

Final Sugar 4,5L =4,5 x Total Sugar / Total Beer Vol

¿Should we see an example?

Temperature of Fermentation = 20ºC

Desired CO2 Volume = 2,5

Total Beer Volume = 20L

Volume of your bottles = 33cl

  • Dissolved Volume = 1,7 - 0,059 x Temp Ferm + (0,00086 x Temp Ferm x Temp Ferm)

Dissolved Volume = 1,7 - 0,059 x 20 + (0,00086 x 20 X 20) = 0,864

  • Total Sugar = (Desired Volume – Dissolved Volume) x (Total Beer Volume) x 3,9

Total Sugar = (2,5 - 0,864) x (20) x 3,9 = 127,608 ≈ 130 grams

  • Final Sugar 33cl =0,33 x Total Sugar / Total Beer Volume

Final Sugar 33cl =0,33 x 130 / 20 = 2,145 grams

¿Some last advices to Brew the perfect beer?

If you follow the above-mentioned calculations and our instruction manuals, you should get the perfect beer, just like a master brewers!

To brew the perfect beer, it is important to work with the best tools. Take a look at our accessories and compact machines to complete your homebrew equipment. 

If you are still not sure about your Dextrose or Sucrose calculations, we also offer carbonation drops. These tablets are very easy to use: Add 1 tablet per 33cl bottle, 2 per 75cl bottle and 3 per 1L bottle. You can find these tablets in our accessories too.

And if you have any further questions or encounter any problems, you can send us your questions to and we will answer any of your questions and doubts.

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