Natural Carbonation in a Keg (How To Do It & How Long To Wait) (2023)

Carbonation is the last (but not least!) step of the brewing process and has a tremendous influence on the profile of the beer. Natural carbonation is a traditional, proven process, but requires more patience than modern alternatives, but what’s the difference?

Natural carbonation occurs during the fermentation process, when yeast consumes sugar, producing carbon dioxide. In an enclosed fermentation, the carbon dioxide remains trapped, saturating the beer and becoming carbonic acid which adds the pleasant fizz to your beer. The process takes two to three weeks and can be achieved in a variety of ways.

Keep reading to learn more about natural carbonation, and how to achieve it in your kegged homebrew.

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What is carbonation?

Carbonation stimulates something called the trigeminal nerve found in your mouth. The purpose of the trigeminal nerve is to sense hotness, coldness, or irritants.

In the context of beer, highly carbonated brews are said to have a slight burning sensation, sometimes called a carbon dioxide “burn.” When a beer is properly carbonated, you should just feel a pleasant tingling sensation, similar to what you’d feel when drinking a carbonated (non-alcoholic) soda.

Carbonation can have a noticeable impact on beer flavor. By stirring volatile aroma compounds in the beer, carbonation helps make them more detectable. In addition to promoting flavor compounds, carbon dioxide influences the top-foam and creamy mouthfeel associated with a good, foamy beer. Carbonation is essential to the brewing process to create a refined result.

Carbonation – as the name suggests – is the volume of carbon dioxide contained within a liquid. The greater the amount, the more carbonated the beverage. On average, an English cask beer has about 1.5 volumes of carbon dioxide, whereas champagne has about 7.0 volumes of carbon dioxide.

The amount of carbon dioxide in a solution is inversely proportional to the temperature of the solution, which means that the colder a solution is, the higher the concentration of CO2.

What is carbonation in beer?

Natural carbonation occurs when yeast converts sugars into carbon dioxide.

Inside the fermentation vessel, the carbon dioxide has nowhere to escape, so it saturates the beer and transforms into carbonic acid (the liquid form of CO2). That carbonic acid then binds to the flavor and aroma compounds in the beer.

Once natural carbonation has occurred and the keg or bottle is unsealed, carbon dioxide rises to the surface and tries to escape. That’s why you see those tiny bubbles rush to the surface of the beer.

Effective natural carbonation creates tiny bubbles, resulting in a fine head to your beer. Natural carbonation can also result in a softer, rounder taste profile in the beer.

Natural carbonation is an age-old carbonation method. Before modern-day brewing equipment, breweries waited patiently for natural fermentation to do the work. It is a simple, but effective method of adding carbon dioxide to your beer. The fermentation process is nearly 10,000 years old, commonly mostly used in the creation of wine and beer.

Fermentation is a chemical process by which glucose and other molecules are broken down anaerobically. The process not only produces alcohol but also carbon dioxide, as yeast digests the sugars in the wort. As a result of the fermentation, a large quantity of carbon dioxide is liable to escape, so the brewer seals the beer in a container towards the end of the process.

Some homebrewers employ another method for natural carbonation in smaller quantities. In this method, the beer is allowed to ferment completely, unfiltered with active yeast still floating inside. The brewer needs only to add a small amount of sugar at bottling time. Once the bottles are firmly sealed, the yeast continues consuming the added sugar, releasing fresh carbon dioxide in the process.

Can you carbonate a keg naturally?

You can carbonate a keg naturally, but most brewers do not choose this method.

Nowadays, it is relatively uncommon to carbonate an entire keg naturally. However, the process is possible and uncomplicated.

Here are some of the reasons why you might choose natural carbonation:

  • Homebrewers who prefer natural carbonation over forced carbonation say the natural carbonation results in a thicker head, smaller bubbles, and more lacing (the ring of foam around the glass that remains after the head dissipates).
  • Natural carbonation requires less equipment than forced carbonation. Those who are just starting their homebrewing journey should choose natural carbonation. It is notably cheaper, but you will have to wait longer to carbonate your beer.
  • Most brewers regard natural carbonation as a traditional method. For this reason, some brewers prefer to go “all-natural.” Since the method has been utilized for such a long time, there are countless tips and resources for reference.

How long does natural keg carbonation take?

There is no strict value, but the general consensus suggests a timeline of 2-3 weeks.

Can you use a keg without CO2?

Using a keg without carbon dioxide is a big no-go.

While it is possible to keg beer without a carbon dioxide setup, beer served without it will spoil much more quickly.

Do not be misled into believing that you can naturally carbonate a keg and serve the beer without a kegging or carbon dioxide setup. The right kegging equipment is of paramount importance.

How to naturally carbonate a keg of homebrew beer

Natural carbonation is when you carbonate a keg of homebrew with sugar. It takes longer than forced carbonation, but the process remains straightforward.

To naturally carbonate your homebrew keg, you will need to:

  • Calculate your priming sugar amount
  • Mix priming sugar into the beer
  • Pour the water into your homebrew keg
  • Set up your fermenter
  • Let your kegged beer condition
  • Refrigerate your kegged homebrew
  • Attach the keg to the carbon dioxide and serve

Calculate your priming sugar amount

You will need to determine how much carbon dioxide you want in your brew. If you are new and have no idea of the correct amount, aim for about 2.3 to 2.5 vols of CO2.

You can also refer to a carb calculator online. Or try this priming sugar calculator to determine the correct amount of corn sugar or DME.

Mix priming sugar into the beer

After you have determined the right amount of priming sugar, heat about a pint of water in a saucepan, in which you dissolve priming sugar.

Mix in your priming sugar and heat the water to a boil. Set the water aside to cool.

Pour the water into your homebrew keg

Once the water has cooled to room temperature, pour the water into your homebrew keg.

You should take care that the keg is clean and sanitized to avoid contamination.

Set up your fermenter

Next, rack your homebrew from the fermenter to the keg.

This step requires additional equipment, namely a siphon.

Let your kegged beer condition

Make sure to properly seal the keg to contain the carbon dioxide (and to exclude contaminants).

Refrigerate your kegged homebrew

Once the keg is sealed, you should leave the keg at a cool temperature. You can refrigerate it if you have the capacity.

If not, leave it in a cool room for about two weeks. Place the keg in a space where the temperature remains steady.

Fluctuations in temperature can stall your yeast or otherwise impede the process.

Attach the keg to carbon dioxide and serve

Before serving your beer, you will still need some carbon dioxide in the mix.

I recommend adjusting the regulator pressure to 10 PSI for serving.

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How long does natural carbonation take in a keg? ›

Of course you can naturally carbonate in a keg by adding the correct amount of sugars and keeping it warm for about two weeks but most people prefer to 'force' the carbonation into the beer using a CO2 cylinder.

How long does natural carbonation take? ›

After you have bottled your beer it generally takes 2-3 weeks for the carbonation process to be completed. This can vary depending on which type of beer you are making but is a good rule of thumb. Make sure you research bottle carbonation times depending on which beer you are brewing.

How do you carbonate beer naturally? ›

Corn Sugar:

Corn sugar is the most common because it does not add any significant flavor contributions and it is pretty inexpensive. For 5 gallons of beer, 4 ounces (again, by weight) of corn sugar should yield you right at 2.5 volumes of CO2 in your beer, which is about average for an American Pale Ale.

What is the process of natural carbonation? ›

Natural carbonation occurs when the yeast converts sugars into CO2. In the fermentation vessel, the CO2 has nowhere to escape, so it goes into the beer and transforms into carbonic acid (liquid form of CO2).

How can I speed up my natural carbonation? ›

7 Ways To Increase Carbonation in Your Homebrew
  1. Add the right amount of priming sugar.
  2. Ensure your bottle caps are tight.
  3. Fill to brim before sealing.
  4. Force carbonation.
  5. Flip your bottles.
  6. Increase the temperature a bit.
  7. Recondition the beer.

How do you speed up keg carbonation? ›

Agitating the keg increases the contact area between CO2 and beer even further, promoting faster diffusion of CO2 into the beer. Continue to shake the keg for 20-30 minutes then lower the pressure to 20 PSI and allow the keg to carbonate for 2-3 days. Check the carbonation levels and enjoy!

Is natural carbonation good for you? ›

“While soda and other carbonated drinks have been associated with negative health effects, carbonation is not harmful in and of itself,” says Saima Lodhi, MD, an internal medicine doctor at Scripps Coastal Medical Center Hillcrest. Drinking plain carbonated water has some health benefits, she adds.

What pressure for keg carbonation? ›

Typically, you'll hook up your co2 to the keg, set the regulator at serving pressure, between 8–12 psi, and let it slowly carbonate over the course of 2 weeks or so. Carbonation charts can be used to ensure you get the exact level you want, with allowances made for temperature.

How long does it take to carbonate a 5 gallon keg? ›

A 5-gallon (19-L) keg of beer usually takes 5 to 7 days to equilibrate. Although this is not the fastest method, the risk of over-carbonation is minimized and the beer is carbonated in a reasonable amount of time.

What is the difference between force carbonation and natural carbonation? ›

With natural conditioning, you prime the beer with priming sugar, keg it, then let it sit for up to two weeks. With force carbonation, there is no priming sugar, and you force the CO2 gas into solution by rocking or shaking the keg. Natural conditioning: Siphon the beer into the keg then stir in priming sugar.

How do you force carbonate a keg? ›

Yes, you read that right.
  1. Connect your keg to the CO2 and turn the regulator to 20 PSI.
  2. Place the keg on its side on the ground.
  3. Roll the keg back and forth in a swift but gentle motion for about 15-20 minutes or until you've reached your desired level of carbonation.
  4. Purge keg to serving pressure (10-12 PSI) and serve.
Oct 27, 2020

Is there such a thing as natural carbonation? ›

Carbonation in mineral water can be natural, meaning the water contains enough carbon dioxide when it is underground to make it fizz.

How do you naturally carbonate a corny keg? ›

I want to “naturally” carbonate my beer.

For this method, you add 1/3 of a cup of corn sugar (not ¾ of a cup like filling small bottles) to the beer, seal the lid with about 20 lbs of pressure from your tank, unhook the Co2, and then let the yeast ferment the corn sugar and also carbonate the beer at the same time.

Can carbonation be natural? ›

The carbonation of sparkling water can occur naturally or artificially. Sparkling or carbonated water forms naturally when volcanic gases dissolve in springs or wells of natural water. This naturally occurring sparkling water often contains minerals such as sodium or calcium.

How long to wait for carbonation? ›


The most accurate and easiest method for force carbonating is often referred to as the “set it and forget it method.” Select your refrigerator temperature and your desired carbonation rate set your CO2 regulator to that pressure, and wait 5-10 days for the beer to carbonate.

What increases carbonation? ›

Water is essential for carbonation, and a relative humidity ranging from about 50% to 70% creates an ideal environment for the reactions to occur. Concrete with a relative humidity lower than 40% is less susceptible to carbonation because there is insufficient water to dissolve carbon dioxide.

How much sugar does it take to carbonate a gallon of beer? ›

1 oz of priming sugar will carbonate 1 gallon of beer. 5 oz of priming sugar will carbonate multiple 1 gallon batches OR a single 5 gallon of beer.

Why won't my beer carbonate in my keg? ›

Forgetting to add priming sugar and not getting a good seal with the bottle cap or keg lid can be another reason for lack of carbonation. The easiest solution to these problems is to dose each bottle with additional sugar.

Do smaller kegs carbonate faster? ›

Since time to carbonate is also a function of volume, smaller amounts of beer carbonate quicker, for example I've carbonated 2 gallons of 38°F beer at 50 psi in right about 5 hours.

Is natural carbonated water safe to drink? ›

Plain carbonated water is a healthy and hydrating beverage choice. Some individuals may experience mild symptoms from too much carbonated water, such as temporary bloating or gas.

What is unhealthy about carbonation? ›

When you drink sweetened, carbonated soda, the sugar remains in your mouth, promoting the processes that lead to tooth decay. The acid in these carbonated drinks further increase the likelihood of developing cavities, because these chemicals also slowly erode the enamel of your teeth.

Can too much carbonation be bad for you? ›

That said, there's definitely such a thing as too much seltzer. “A large intake of seltzer in a short period of time may cause gastric distress or bloating and can weaken a valve that typically keeps stomach contents down,” Manning says.

What temperature do you carbonate a keg? ›

The 24 Hour Beer Carbonation Method

Chill the beer to to serving temp (45F), keg and purge with CO2, apply gas at 45psi and leave sit for 24 hours. You should have carbonated beer in 24 hours.

Does a keg need to rest before tapping? ›

Let It Settle Before Tapping. When you get your keg, try to be gentle with it. It doesn't matter how large or small it may be, it is important that you try to limit how much you shake or roll it around. It's always wise to let it sit idle for a few hours before tapping it.

How long should you be in a keg before drinking? ›

It is important to get your keg cold before serving. Chill your keg for 4-5 hours before tapping to avoid warm and foamy beer.

How long to carbonate a keg at room temperature? ›

Re: Force Carbination at Room Temperature

I simply chill the beer and set the regulator to 30 psi for 48 hours, and that does the trick. During the summer, I usually carbonate naturally using sugar.

How much sugar do I need to carbonate 5 gallons of beer? ›

Corn sugar, a.k.a. dextrose or priming sugar (all terms are interchangeable) is the classic sugar used in priming beer and gives consistent carbonation without greatly affecting flavor. Use it at a rate of 1 oz. per gallon of beer (or 5 oz. per 5 gallon batch, about 3/4 cup) to prime beer for bottling.

What PSI for forced carbonation? ›

To burst carbonate your homebrew, crank up your CO2 regulator to 30 psi for 24 hours. Then reduce down to normal serving pressure, which is around 12 psi to15 psi (depending on your beer line length and altitude). That should leave your beer 75% carbonated.

What PSI should soda be carbonated at? ›

Soda is also dispensed at a higher p.s.i. than beer. You want your pressure set at 5-10 p.s.i. for best results. Do not bottle your soda.

What PSI is beer carbonated at? ›

The amount of CO2 dissolved into the beer depends on the external pressure and the temperature. For example to carbonate a Porter at 40 degrees F requires that the beer be pressurized at 6 to 7 psi. “Psi” simply means pounds per square inch and just measures how firmly the gas is being compressed.

How do you naturally carbonate a keg spunding valve? ›

A Spunding Valve allows you to maintain a set pressure. If pressure in the vessel exceeds the set point, it is expelled. It generally consists of an adjustable PRV valve, a tee, a gauge and a way to connect to your keg.

How many pounds of CO2 does it take to carbonate a keg? ›

If we're talking a quarter barrel of draught beer (7.75 gallons), it will take about half a pound of CO2 to dispense it. However, if you, like most homebrewers, prefer to use 5-gallon kegs ( Corny kegs), you will be able to dispense about 31 to 44 kegs of beer with a 5-pound CO2 tank.

What makes a keg foamy? ›

When the temperature rises above 40 degrees, the CO2 gas starts to escape from the beer, and this is what causes foam (in most cases). For this reason, temperature issues constitute the great majority of problems with kegerators serving foamy beer.

What are the methods of carbonation? ›

There are two common carbonation methods: the forced carbonation method and the bottled carbonation method, which includes variations such as the traditional champagne method and the Charmat method.

Can you carbonate a keg without CO2? ›

Yes you can naturally carbonate kegged beer. I carbonate all my beers this way and prefer it since I have found when I naturally carbonate beers I still have to wait to let them age. I recommend you pressurize the keg with CO2 to seal it.

Can I carbonate beer in a keg with sugar? ›

Kegs can also be primed with sugar, the same way that bottles are. Boil the sugar in some water to dissolve and add to the beer in the keg. You will need use CO2 to put some pressure in the keg in order to seal the lid (I use 10 lbs of pressure to seal my kegs.).

How do you carbonate a drink without SodaStream? ›

The principle is that you can add lemon juice, vinegar, or citric acid to water, then pour a bit of baking soda in the container—and voilà! The acid in the water mixes with bicarbonate of soda (baking soda) to create carbon dioxide gas. The generated bubbles of CO2 make the drink fizzy.

Is club soda the same as soda water? ›

Club soda is similar to sparkling water because it also has some minerals. However, the biggest difference between the two is that manufacturers add carbonation and minerals after the fact. They don't occur naturally in club soda like they do in sparkling water.

Is club soda the same as soda? ›

Club soda is infused with mineral salts to enhance its taste and fizz. These include potassium sulfate, sodium chloride, disodium phosphate, and sodium bicarbonate. Seltzer is made similarly to club soda but generally doesn't contain added minerals, giving it a plainer taste.

How do you carbonate a keg in 24 hours? ›

Steps to Force Carbonate your Beer:

CO2 dissolves into beer much more easily when the beer is cold, so ideally, place keg with gas line attached into fridge and leave under pressure for about 24 hours. Adjust pressure down to 20 PSI for 24 hours.

How do you pressurize a keg without CO2? ›

Use a bicycle pump with a needle used for blowing up sports ball to replace the CO2. Attach the needle to the CO2 line and use duct tape etc. to secure it. Once you have made sure there is no leakage occurring, begin pumping and open the tap. The liquid will begin to flow out of the tap without the need for siphoning.

Do you need to force carbonate a keg? ›

One of the great joys of home brewing is drinking that first batch of home brew from a keg. In order to do that you must carbonate your Cornelius Keg. There are essentially two ways to do that – forced carbonation and natural carbonation using corn sugar. Forced carbonation is by far the best way to go.

How do you carbonate beer in a keg naturally? ›

Of course you can naturally carbonate in a keg by adding the correct amount of sugars and keeping it warm for about two weeks but most people prefer to 'force' the carbonation into the beer using a CO2 cylinder.

How long does a keg stay fresh without co2? ›

Since a picnic pump uses oxygen instead of carbon dioxide, a tapped keg will only last about 12-24 hours depending on the type of beer and how much oxygen was pumped into it.

How long does it take to carbonate a 5 gallon keg of beer? ›

A 5-gallon (19-L) keg of beer usually takes 5 to 7 days to equilibrate. Although this is not the fastest method, the risk of over-carbonation is minimized and the beer is carbonated in a reasonable amount of time.

How do you carbonate a keg in 30 minutes? ›

Chill the beer to serving temp (45F), keg and purge with CO2, apply gas at 50psi. Remove from gas and shake for 5 mins. Re-pressurize, remove from gas, shake for 5 mins. Repeat 1 more time.

How long does it take to condition beer in a keg? ›

Your conditioning method determines how long your beer needs to condition in a keg. If you are using the shake method, your beer will need to condition for just 2-3 hours. If you use the burst method, allow it to go for 12-24 hours. However, if you follow a slow method, it may take 10-14 days.

How long does a keg need to rest? ›

A: You tap a keg by using a keg coupler.

If there has been excessive agitation during transportation, allow the keg to settle for 1 to 2 hours before tapping. Make sure the beer faucet is in the off position prior to tapping.

How long does it take for a keg to not be foamy? ›

Once a keg is installed into your kegerator, you should give it at least two and preferably four hours to 'settle in' before pouring. Also, make sure you are pouring with the glass at an angle, and this will help reduce foam from an improper pour.

What PSI should I carbonate my keg? ›

For the first day or two of carbonation, apply 30 psi or so to the keg. You might even give the keg a good shake from time to time to help encourage the gas to go into solution. After one or two days of this, drop the pressure down to 12 psi, depressurize the headspace, wait another 2–3 days, and you're good to go.

Can you over carbonate a keg? ›

You Over Carbonated Your Beer

An over carbonated keg can also be detected by looking at the beer line for small bubbles coming up from the keg, as co2 tries to escape the head space. To fix this, unhook the co2 and purge the head space.

What PSI should I carbonate my beer at? ›

For lagers, a regulator set between 10 and 14 psi works best. Continental and light pilsners require slightly higher CO2 regulator settings, from 11 to 16 psi. Wheat beers, Belgian beers, and common American sours are generally the most carbonated beers, requiring about 15 to 20 psi.

Does keg have to be cold to carbonate? ›

Just a quick note before I dive in, chilled beer accepts CO2 much better/quicker than warm beer. You can still carbonate a warm keg, it will just take longer.

What happens if you keg beer too early? ›

The main detractor in kegging too early is the amount of yeast solids your keg will have. That's not a big deal to me. I actually keg all of my lagers early so that the keg will be spunded.


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