Keg Maintenance


Poor hygiene is the leading factor affecting the quality of draft systems. Besides the health and safety of the customers, there are numerous other problems such as organoleptic alteration or the accumulation of bacteria that can affect the cleanliness of the draft line and the quality of the beverage served.

When draft systems are not properly cleaned, harmful microorganisms will begin to grow in the draft lines and associated equipment. It is therefore essential to implement a well-designed and regularly executed maintenance plan to ensure trouble-free draft system operation, and, to of course ensure a fresh beer packed full of flavor.

Best practice for cleaning frequency varies around the world and is influenced by many factors such as cellar temperatures, distances between keg and tap as well as dispensing temperatures.

Because every draft system is different, there is no definitive procedure for cleaning. There are, however, certain cleaning principles that can be applied to every system. In order to be effective, cleaning solutions need to come into contact with every single point of the draft line as well as every part of the associated equipment.

Despite the fact that some items like couplers and faucets can be hand cleaned, most of the system can only be reached by means of fluid flowing through the draft lines. The industry currently uses two cleaning procedures: recirculation by electric pump, and static or pressure pot cleaning.

  • Electric recirculating pump cleaning uses a combination of chemical cleaning and mechanical action to clean a draft system by increasing the normal flow rate through the lines during the cleaning process.

  • Static or pressure pot cleaning, for example THIELMANN Cleaning Can, is the best alternative for short runs of less than 4.5 m/14ft 7’’. This procedure is a versatile cleaning solution not only for beer but also for soft drinks dispensers. Cleaning Can pressure cleaning is the simplest solution to keep draft lines clean, since this method only requires the substitution of the keg by the Cleaning Can during the washing process

Cleaning Can has a maximum working pressure of 5 bar and is made of stainless steel EN 1.4301 (AISI304).

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Pressure pot cleaning, also known as “static cleaning” allows cleaning solution and draft line to be in contact for no less than 20 minutes. They can be equipped with various keg valves to clean up to five different system lines at once. It can have a different valve for all the couplers available and it can also be combined with jumpers to clean up to 20 lines in a single pass.

Once finished, the Cleaning Can simply needs to be untapped and the line re-tapped to the keg...easy!

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Now that you know how to keep your draft lines clean and your beer tasting great through effective draft system cleaning, let’s talk about the importance of keeping your keg fleet in top condition.

A keg fleet is only as strong as its weakest keg

Even though stainless steel kegs are more likely to withstand rough handling in the brewery or in transit – damage can still occur. Added to this, beer is becoming an increasingly international beverage with consumers wanting to try beers from all across the world, wherever they are.

This however, means that beers and their packaging – kegs, are travelling further distances than ever before and as they move through more complex supply chains, the likelihood of them being damaged, lost or stolen increases.

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The preventative aspect of servicing is vital, particularly for brewers operating on a smaller scale, where problems with a keg aren’t usually discovered until the keg leaks, the beer goes bad, or it doesn’t dispense properly anymore.

While all this has an effect on profits, so does the impact of having kegs out of service unnecessarily.

For a large-scale brewery with a keg fleet that numbers in the millions, there is more flexibility in the operating schedule of those kegs. The issue becomes more critical as the size of the keg fleet reduces; the smaller the fleet, the bigger impact each keg has on the overall brewing operation.

At this level, a smaller brewer simply cannot afford to have a keg not operating efficiently, or out of service, at any time. Kegs need to be operating at optimal levels continuously because every single keg represents a larger proportion of the overall brewing capacity of the brewery. The knock on effect can affect profit margins.

As an essential asset in any brewery, kegs require regular maintenance and servicing to keep them in top condition. The good news is that stainless steel kegs can be repaired easily and also cost-effectively. Stainless steel material delivers hygiene standards and it protects beer from UV light, pollution particles and corrosion. With stainless steel kegs, brewers can get durable, sterile containers that can be used up to a 30-year period.

Kegs that are maintained under a regular servicing schedule will also experience less down-time (better profit margins…woohoo!), a longer life span, and will continue to deliver the perfect brew, time after time.

Working on Kegs and Keeping it Safe!

By: Steve Bradt
Eastern US technical Sales Representative for Micro Matic’s Packaging Division


I travel the Eastern US working with brewers who use kegs as part of their packaging mix. As a “recovering” craft brewer I came into this position painfully aware of how little most of us know about that ultimate beer can that we love so much.

There is a lot to say about the ways that kegs can affect the quality of your beer, but the first thing to be addressed is safety. At most stages of a keg’s life cycle, it exists as a pressurized vessel and as such, it deserves some respect. A full explanation of keg servicing and safety is beyond the scope of a blog post, but let me offer a few key tips to help keep you, your crew, and your customers free of injury.

Note that while periodic removal of spears for repair or inspection is a good practice, the practice of removing spears to wash kegs is not. This greatly increases the likelihood of an accident. A well designed, commercial keg washer that will allow cleaning of the keg without disassembly is an essential piece of equipment for commercial brewers of all sizes.

The overarching safety requirement is that you must always depressurize the keg immediately prior to attempting to remove the spear. It seems like a simple concept, but it gets ignored surprisingly often. And the “immediately” part is critical, because a keg that has beer in it will re-pressurize over time and even an empty keg will re-pressurize as it warms up.

Drop-in style spears are the most common in the American Sanke or D-system kegs. They are secured by a double circlip made of flat stainless steel that snaps into a groove in the keg neck.

·       Ignore everything you’ve seen on YouTube. It’s wrong and in many cases dangerous!

·       Use the correct tools. These are specifically designed and supplied by keg or spear manufacturers. This does not include hammers, creatively modified screwdrivers, ice picks or vice grips! The safest tools will provide a way to clamp down on the spear to depressurize the keg and relieve the pressure against the circlip by compressing the sealing gasket. This a often called a “Valve Compression Safety Tool” This allows for the insertion of a special stainless steel “knife” to remove the circlip without damage to the keg or the spear.

·       Always keep your body out of the spear’s path of ejection while removing the circlip.

·       Always discard and destroy the circlip when you remove it. These are one-use items and a brand new one should always be used for reassembly of the keg. Really – every time.

·       Tabs on the spear fit into notches in the keg neck and then rotate slightly clockwise into a safety “Z groove” that is designed to help prevent the spear from accidentally ejecting from the keg.

·       The same clamping tool that was used to relieve the pressure against the circlip for removal is used again for reassembly. This allows you to put your new circlip in with no other tools besides your fingers. No other tools should be used as they may cause damage to the circlip.

o   Pro Tip! If the circlip doesn’t go in all the way, loosen the valve compression tool, rotate it 90° and tighten it again. If you repeat that for 360° and the circlip still hasn’t gone  into the groove, take it back out and figure out why. Either the groove is dirty (clean it) or it has been pinched (this may not be repairable) or you neglected to lock the spear into the safety Z groove and the tabs are blocking the groove (You may need to straighten the tabs before reinserting).

Threaded spears have their own set of safety rules, but that can wait for another post. 


Steve Bradt is the Eastern US technical Sales Representative for Micro Matic’s Packaging Division. He  provides training and technical support for brewers using Micro Matic Keg Spears and Tools. Prior to coming to work for Micro Matic, Steve spent nearly 30 years as a professional brewer - ranging from pub scale operations to a 10,000 bbl./yr. production brewery, where he developed a strong affinity for technical troubleshooting.