How to clean beer tap systems

How to Clean a Draft Beer System

There are several beer system setups commonly found in bars and breweries, including kegerators, direct draw, and long draw systems.

Each draft system uses beer lines to transport beer from kegs to the tap. No matter the length of the line, biofilm consisting of bacteria and yeast eventually grows inside it, feeding on the proteins and carbohydrates in beer and degrading its flavor and quality. The longer a beer line is left uncleaned, the harder it is to remove this biofilm.

Operators should regularly clean beer lines for the freshest, cleanest beer. This article outlines how to clean beer lines properly and safely.

Understanding Draught Beer: Anatomy of a Beer System

Draft beer systems are highly customizable, with towers holding anywhere from 1 to 20 faucets from different beer kegs. Flexible beer lines feed each faucet. These lines come from a chilled keg stored in a kegerator or walk-in cooler. Each keg coupler has two lines attached to it: one is the beer line heading towards the beer tower, while the other receives gas (normally CO2, nitrogen, or a mix of gasses), which keeps the keg pressurized for beer dispensing.

To maintain this system, operators must clean every part that contacts beer; this includes couplers, lines, shanks, and faucets. The Brewers Association provides a guide for cleaning long draw systems. It recommends balancing four cleaning factors: time, temperature, mechanical action, and chemical action.1 If one of these is limited, the system cleaner needs to increase the other factors. For example, if it's impossible to create mechanical action by circulating cleaner through a system, then you must rely on a longer cleaning time or higher concentration of cleaning solution.

beer system infographic

Beer Line Cleaning Steps

The following steps outline how to clean a long draw system using the electric recirculation method. This process is the costliest, but it yields the best results in complex draft systems.

Safety First

Cleaning beer lines involves using caustic or acidic chemicals, which can cause injury if they contact skin and eyes or are ingested. Use the proper protective equipment: chemical resistant gloves, safety glasses, and nonslip, closed-toe shoes.

  1. In the walk-in cooler, turn off the glycol power pack and disengage all beer couplers
  2. Connect the couplers to each other by using a cleaning adaptor. The Brewers Association recommends cleaning a maximum of four lines in series to maintain a high flow rate for mechanical action
  3. At the bar, remove the faucets from their shanks and connect the shanks with jumper hoses to create a loop. The cleaner will flow toward the kegs in one line, through the connected couplers in the walk-in cooler, then back to the shanks through another line, filling each line in the series
  4. Use a pump to flush out beer in the system with water. Do this by connecting the output side of the pump to the first shank in the series and the input side to a bucket of warm water (80-100 degrees F). Position a tube from the last shank in the series into another bucket or nearby sink to flush out the beer. Try to achieve a flow rate higher than the usual beer flow rate (aim for 2 gallons per minute)
  5. Once the system is filled with water, mix enough caustic cleaner with the water in your bucket. Use a 2 percent dilution—or 3 percent for old or especially dirty systems—based on the total water in your bucket and in your system. Note: Always add the cleaner to the water to avoid splashing and unanticipated reactions
  6. Move the tube that's draining water to the bucket with caustic cleaner in it to create a closed loop. Use the pump to run the caustic cleaner through the system for 15 or 20 minutes depending on flow rate; a higher flow rate requires less time.
  7. While you are waiting, ensure the rest of the system is clean. Make sure you know how to clean keg taps by taking them apart, soaking the faucets in caustic solution, and wiping down the couplers
  8. After letting the caustic solution circulate, flush the lines once more with water
  9. Ensure no caustic solution is left in the system by testing the output with pH paper. Look for a neutral pH of 7
  10. Disconnect the jumper hoses from the shanks, clean the shanks by hand, and replace the faucets
  11. Reconnect the couplers to the beer kegs and open each faucet to drain water from the lines until beer starts to flow
  12. Turn the glycol system back on and clean up any mess. Check your caustic container for instructions on proper disposal

FAQ - What to Know About Cleaning Your Beer System

Do I need to hire a professional to clean my beer system?

While not required in most settings, hiring a trained professional can help ensure your system is cleaned correctly. Regardless of who cleans it, make sure to periodically inspect the cleanliness of your system.

How often should you clean a draft beer system?

Clean your system every two weeks with caustic solution to remove bacteria buildup and every quarter with acid cleaner to remove water stone and beer stone—a hard buildup that comes from minerals found naturally in beer.

What chemicals should I use to clean a draft beer system?

Use an alkaline caustic cleaner specifically designated for cleaning organic buildup in beer lines. Most caustic cleaners have sodium hydroxide, potassium hydroxide, or a combination of the two. Acid cleaners use mixtures containing acids like phosphoric acid. Avoid using chlorine, sulfuric, hydrochloric, or nitric acid.

How do I tell if my draft beer system needs cleaning?

The most obvious indicator of contamination is visibly dirty beer lines. You can also check for biofilm buildup by scraping the inside of a faucet with a straw. Dirty draft lines harboring bacteria colonies also cause off-tasting beer with a buttery or sour flavor.

Are there other methods for cleaning a draft beer system?

There are several methods for cleaning draft beer systems. Some use pressurized canisters to force cleaner through the line; this style usually requires more time and effort. Smaller systems like kegerators and direct draw use a hand pump to move cleaners through the tubes. Electric recirculation is recommended for large systems, as it's the most efficient and thorough method.

When should I replace my beer lines?

Replace beer lines every 1 to 2 years, after a flavor or bacteria contamination, or if they have been compromised in any way.

How to clean kegerator lines

Kegerator lines also need regular caustic and acid cleaning. Since their lines are much shorter, a hand pump should suffice.

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References

  1. Draught Beer Quality Manual. Fourth Edition. Brewers Association. Accessed July 2025