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July 4, 2021

Foamy Beer | How to Fix Foaming Issues With Draft Beer Systems

Do you have foamy beer issues? If so, the problem is usually related to one of these things:

  • Wrong Restriction Value or Wrong Beer Line ( found in the beer line used)
  • Wrong Temperature (dispensing beer at 38 F)
  • Wrong Applied Pressure (Making sure gas pressure equals the restriction value).

This blog post will discuss how to solve foamy beer problems by discussing each possible cause and how to fix it. So you can pour clear beer...not foamy beer.

For a more in depth guide about beer fundamentals check out this post.

If you would like a Free Beer Trouble Shooting Checklist Click Here. I put this together for my clients I clean beer lines for. It goes over common problems and solutions for all 3 types of beer systems: Direct Draw, Remote Systems, and Air- Cooled Systems. It's the aqua marine button. Click on that for the guide.

Foamy Beer Due to Temperature

What causes beer to foam ? In general, beer will foam when it's served too cold. It will also foam if, and usually the more common issue is it's too warm. Have you heard this saying before ? Beer keeps foaming after opening. If your keg is stored in an area with a constant temperature, then you need to make sure the temperature of the beer inside is also constant and cold. 

Maintaining consistent refrigeration (38 degrees F) is important. One way to check where your beer temps at is by taking a digital thermometer, pouring some beer, and temping it. Where we want to be is 38 degrees. When beer is served warmer, it becomes unstable foams because there is too much foam in the keg.

The other place to check the temperature is inside the kegerator or beer cooler. Check the temperature by placing a glass of water in there and letting it sit for 24 hrs, then use a digital thermometer to check it.

By checking the kegerator, beer cooler and temping the beer from the faucet. You will know if it's a temperature issue or not. The target temperature for optimal dispensing is 38 degrees Fahrenheit.

Remote System Chiller

Now if you're using a remote system, and you have a glycol chiller in your draft beer set-up. You'll need to check your glycol chiller. The temp should be set anywhere from like 29°-32°. I usually keep these set at the manufacturer's setting. I rarely change this. This is also another place to check for temperature issues and you'll know if you have a glycol chiller issue. If the digital thermostat isn't reading 29-32 degrees. This is your problem.

Sometimes a problem for glycol chiller's will be in the pump and motor area. Sometimes the pump is malfunctioning and not actually pumping glycol through your draft beer system and you'll need to replace the pump.

Typically what happens is that your beer system will be temping at a very high temperature maybe like 60 or so degrees at the faucet, but your glycol bath will be temping at 32. This just says that your glycol isn't circulating through your beer system and another problem that I've come across in the years, is the glycol chiller thermostat malfunctioning.

A Solution to these problems is contacting your local draft technician or your local refrigeration company that deals with the chillers to fix the issue.

Using The Wrong Beer Line 

If you use the wrong beer line for a kegerator, then foaming can be an issue. In this case, you need to replace your beer line with one that's appropriate (a standard draft beer line).

Since we are most likely addressing a kegerator. The type of beer line you want to use is a 3/16" I.D. vinyl lineTypically it will be about 4' in length and will have a restriction value of 3 lbs per foot. So it will have a total restriction value of 12 lbs.

So what's important about the 12 lbs of restriction? We want to match the applied pressure from the C02 regulator and the Restriction value from the beer line. This will allow the beer to pour at 2 oz's per second, and pour clear beer, while maximizing keg yield.

The next question is how do we determine the right length of beer line for our kegerator? In the example, I used 4', but that can vary depending on the units of carb dissolved in a beer. 

Units of CO2 are simply the amount of dissolved CO2 in a beer. Each beer has its own carb value. 

Use the Carbonation Chart to Determine Line Length

Here is a carbonation chart below to show the pressure and restriction value based on the type of beer or units of carb. To use this chart  find out how cold your cooler is. 2nd, find out what the beer is carbed at. To find this out exactly reach out to the brewery. On average for most ales and lagers I figure 2.5 volumes of C02, but every beer will vary slightly. If this isn't used right you'll probably hear this saying  "keg beer is flat and foamy."

For example let's say we want to pour a beer  carbed at 2.5 volumes of C02 and the temperature of my cooler is 37 degrees. So I would need to apply 11.9 lbs of C02 pressure for my beer to stay in equilibrium. Next we would want to match that value with restriction. 3 lbs per foot in 3/16" I.D. beer vinyl line. For a total of 4' would equalize our applied pressure and ensure our beer pours properly.

Picture of C02 Carbonation Chart

C02 Chart

Applied Pressure Causing Foamy Beer

If the foaming issue is related to applied pressure, then we need to adjust it. In this case, you want a gas regulator with an adjustable knob or dial so that you can make adjustments. Based on what type of beer being dispensed and its carbonation level

We want to set the applied pressure at 12 lbs, this is what we used in our previous example. The key thing here is that foaming won't be an issue if you use a regulator with adjustable knob or dial and target setting of 12 psi.

If the applied pressure is higher than the restriction value the user can experience foamy beer. Also, if the pressure is too low it won't push the beer through the lines properly causing it to foam. This is why it is important to match the restriction value and applied pressure from the gas source.

Determine Carbonation Value if You Don't Know

One trick you can use if you are a bar owner or pub manager to determine the right applied pressure of C02 on your keg is tap a new keg that you're sure is cold.

Adjust your primary regulator to 5 lbs. Next grab a flashlight and get someone to pull the tap on that specific keg for a second. Shine the light right above the keg coupler connection. You should see bubbles leaving the keg and into the jumper line.

Increase the pressure 2 PSI and do the same thing. You should start to see less bubbles. You will repeat this process until you don't see anymore bubbles leaving the keg. This will tell us what are keg is carbed at, and what the right applied pressure should be.

Remember it needs to be a new keg and at a dispensing temperature of 38 degrees.

Other Possible Beer Foaming Issues

Pouring A Beer Wrong

As simple as this sounds. Some bartenders and people don't know how to pour a beer correctly. You want to hold the glass at a 45 degree angle with the beer faucet just above the glass. Pour the beer till about 3/4 of the way filled. Tilt up to get a good head on the beer and shut off the faucet.

Dirty Beer Lines

Cleaning beer lines is an important part of having a draft beer system. This is recommended every 2 weeks with a caustic clean, and an acid clean every quarter. If the lines aren't cleaned properly beer stones and dirty lines can cause the beer system to pour poorly. Also, the beer will suffer in flavor and taste.

Warm Keg

Sometimes Kegs are delivered or tapped when they aren't at 38 degrees. When this happens they will pour foam. Temp the beer from the faucet. If the keg is warm the best thing to do is 86 it, leave it in the cooler for 24 hours so that it can get back to temperature.

Malfunctioning Beer Equipment 

Every once in a while malfunctioning beer equipment can be the cause of foamy beer. Usually, I start at the keg coupler and make sure the jumper line from the coupler to the faucet and shank is full of clear beer.

If there are air-bubble in the line check the gasket inside the beer nut. If it's not sealed correctly this can cause excessive foaming.

The other piece of equipment to check is the beer faucet itself. Make sure the gasket seal inside the beer faucet is resting correctly and there are no tears in it.

Sometimes kinked beer lines get trapped in between kegs and this can cause excessive foaming. By looking over the dispensing equipment really quick. This will also check off the equipment as the culprit.


In this blog post, we talked about the main 3 things that are responsible for foamy beer. This is beer temperature, the restriction in the beer line, and the applied Co2 pressure to push the beer through the system.

On top of that, we briefly talked about some other factors that can increase beer foaming from a draft system. Pouring a beer the wrong way, dirty beer lines and malfunctioning beer equipment.

 By reading this post someone can figure out how to solve the foamy beer issue and have a great pouring system.

If you have any more questions you can always reach out us here. I encourage you to check out our blog for more draft beer dispensing resources, as well as our recommended products


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About the author

I've been a draft beer technician for over 10 years  building, designing, and installing large commercial beer systems. Through the years I've worked on breweries, tap houses, casinos and stadiums around the country.

I enjoy sharing my passion for draft beer dispensing by talking about it, recommending dispensing equipment I've used in commercial installs, or private settings. 


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