Bottle Conditioning Vs Forced Carbonation in a Keg (Pros & Cons)

Unless you prefer non-carbonated beers, you will want to learn how to carbonate your homebrew beer. Carbonation can be added using a couple of different methods.

The bottle conditioning method has the advantage of being cheap to sustain after the initial investment but takes longer. The forced carbonation method is quicker and leaves no additional sediment in the beer but has a higher initial and operating cost. After reviewing the relevant benefits, I recommend bottle conditioning for most homebrewers.

Keep reading to dive into the various pros and cons of each method. What is right for one homebrewer may not be right for another.

What is bottle conditioning?

The first method for carbonating beer is bottle conditioning. Compared to other options, this one is the most natural.

Bottle conditioning is the process of carbonating beer in the bottle. All it takes is a bit of priming sugar added to the beer just before bottling and sealing. The sugar will be consumed by the leftover yeast and turned into CO2.

This process is also called bottle refermentation because it is essentially a smaller fermentation after the initial one. Both stages generate carbon dioxide, but the initial fermentation doesn’t retain the COas well.

In order to get that nice carbonated beer, you need to introduce more CO2. Adding priming sugar to the sealed bottle ensures that the carbon dioxide has nowhere to go besides the beer. 

Bottle conditioning can be done with a bunch of different sugars. Some beer kits will come with priming sugar, but if it didn’t or you’re not using one, you get to pick the sugar

Once you’ve picked what type of sugar you’re using, you’ll need to figure out how much to use. Calculators such as this one will help. More sugar will result in more CO2.

After that, you boil the sugar in water for about 10 minutes and add it to your bottling bucket.

Speaking of bottling buckets, if you’ve never bottled beer or bottle conditioned before there are a few things you’ll need:

You will also need to sanitize everything that will touch your beer. You should already have a good supply of sanitizing agents on hand.

If you want to invest in extra tools, some tools make bottling easier such as bottle fillers.

After the sugar has been added and mixed in, start bottling!

The sealed bottles should be placed with the cap up, never on its side. Additionally, they should be stored at room temperature.

Now we wait.

Give your beer at least two weeks to carbonate. If the beer has a high gravity it will take longer to reach the desired carbonation.


  • Inexpensive
  • Simple
  • Improves flavor over time


  • Can cause bottle bombs
  • Takes time
  • Requires specific storing conditions
  • Adds sediment to bottles
  • Requires an initial investment

Can you bottle condition in a keg?

If you’d rather stick to kegging rather than bottling you can still use this method.

Bottle conditioning in a keg follows the same basic principles of traditional bottle conditioning – in this case, is just a little bigger. Follow the process just like you would if you were bottling but instead of adding the priming sugar to a bottling bucket, add it to your keg.

The only potential issue with bottle conditioning in a keg is that the process results in sediment at the bottom of the container. While it is still drinkable, it might look odd. There are a few ways around this:

  • Cut the end of your pickup inside the keg so that it is an inch or two above the bottom. This way it shouldn’t suck the sediment into your glass.
  • Jury rig a filter on the pickup end. It may take some doing to get it right, but you shouldn’t have to worry about sediment.
  • Simply pour out the first few glasses that have the sediment in them. Some may call it alcohol abuse to toss a perfectly good beer but what can you do?

What is forced carbonation (kegging)?

The forced carbonation method is a more modern approach to carbonating beer.

Forced carbonation skips the production of CO2 using priming sugar by adding it directly to the beer. To force carbonate you need to introduce the gas in a pressurized container such as a keg. Over time, the CO2 will be absorbed into the beer.

To begin, you’ll need several items that are unfortunately different than the items required for bottle conditioning.

Once your beer is finished fermenting, you’ll want to rack it into a secondary fermenter so that you can remove the trub. Before you transfer to your keg you should let the beer rest at room temperature for a day or two.

Without letting it rest, you will likely have an increase in off-flavors. The most notable cause for these off-flavors is diacetyl. It brings a buttery popcorn taste that may be an odd addition. 

After it finishes resting you can transfer your beer to the keg.

At this point, you have two options. You can hook the CO2 canister and gas regulator to the gas post or you can attach them to the liquid post. 

The latter option sends the gas through the dip tube to then rise from the bottom. It is meant to give the gas more surface area to be absorbed, but its functionality is debated among homebrewers.

To use the liquid post for gas you will need to switch the gas and liquid sockets.

After connecting the gas to your keg you will need to consult a forced carbonation chart. The PSI you set your regulator to will depend on how cold your keg is and how carbonated you want your beer.

Though it may seem appealing to get your keg as cold as you can, it isn’t recommended. Different beer styles will do better with different temperatures. 

Once the temperature and PSI have been decided, let your beer carbonate for a week to 10 days.

If you want to force carbonate faster, you can gently shake the keg for about 20 minutes. After shaking, let it sit for three to four days.

Both methods can be done for longer if, at the end of the recommended times, your beer is not as carbonated as you would like.


  • Quicker
  • Little to no sediment
  • No bottle bombs


  • Requires an initial investment
  • Doesn’t improve flavor over time
  • Can’t easily move the keg

Can you force carbonate and then bottle?

What about when you want to take the force carbonated beer somewhere that it would be cumbersome to bring your keg?

It is possible to force carbonate in a keg and bottle after. It is most easily accomplished using a tool called a beer gun.

There are other ways to bottle beer after force carbonating it in a keg, but if this is something you want to do often it would be best to invest in a beer gun.

Once the beer has been properly carbonated in your keg, hook up the beer gun to the CO2 and the keg.

First, fill the bottle with carbon dioxide to remove all oxygen from the bottle. 

Then, fill the bottle with the beer until it starts to overflow. Removing the beer gun from the bottle will leave enough headspace.

After that simply cap the beer like normal.