What types of beer couplers are there?

When you travel to the UK or America, your phone charger isn’t compatible with their sockets. Just like when you want to unscrew a screw, only one specific screwdriver will work. The same thing happens in the beer world: there’s no universal standard for certain components. That’s the case with keg couplers. There are more than eight systems, with the best known being A, D, G, K, L, M, S and U.

However, they all serve the same purpose: they allow gas to enter the keg, usually CO2, which counter-pressurizes the beer so it flows through the tap without generating extra foam and prevents the drink from going flat. Therefore, we have two connections: one gas inlet and one beer outlet; and on each of them, a check valve that seals the system. Although some may have brass parts, the surface that comes into contact with the beer is always made of stainless steel, which is ideal for food use.

So what should we look at when choosing one keg coupler model over another? This is something we must check with our beer supplier to make sure that the coupler we purchase is compatible with the beer keg they provide. But let’s look at some examples.

• Type A Coupler: used by most German brands such as Paulaner, Franziskaner, or Weihenstephan. You’ll find it on many wheat beers.
• S-Type Coupler: in Spain it is mainly used by beers from the Heineken-Cruzcampo and Mahou-San Miguel groups (in this case it is a version of the coupler with 3 lugs or hooks).
• D-type coupler: not very popular on the Iberian Peninsula; its use is limited to North American brands such as Miller, Modelo, and Coors. It is also used by most American craft breweries.
• G-type coupler: used by Estrella Galicia and Estrella Damm, as well as other international brands such as Budweiser or Fullers.
• U-type Coupler: used by Guinness and Kilkenny.
• Type M Coupler: used by Schneider or Veltins, among others.
• Type L Coupler: the least common, but we can find it on uncommon kegs, alcohol-free beers or radlers.
• K Coupler: only compatible with plastic kegs that incorporate an inner bag (like a bag-in-box). We find it on KeyKeg kegs and on other manufacturers that use the KeyKeg system. Almost always associated with craft beer.

In addition, there are some craft breweries and homebrewers who use Corny or Cornelius kegs that require pin-lock or ball-lock couplers, which are specific to this type of container.

So are all the couplers the same, or are there differences between them? Beyond each company’s choice of one valve or another for their kegs, there’s no clear advantage of some models over others. The important thing is to know which connector the new beers you want to add to your taps use, so you’re not caught off guard.

If you need to purchase any coupler for your draft beer setup, Install Beer has all the different types so you can serve whichever beer you like. You can now expand your beer offering without worrying about equipment availability.