Beer, beer, everywhere. And how does it get from here to there? Historically, beer vessels were made out of wood by skilled craftsmen called coopers, but today the vast majority of large-format distributed beer for sale is packaged in kegs. There are however a sparse handful of mostly European breweries that still sell or store some of their beer in wooden casks. Wooden barrels continue to be widely used to age, condition, and store specialty beer, wine, and spirits by the beverage industry as a whole, but even cask-driven UK style beer and “real ales” are more frequently stored in kegs these days for cost, mobility and microbiological reasons.
So kegs are in. You know them already, from work, hobbies, or college parties (though you may not have the clearest of memories). It’s useful to know that there isn’t just one kind, size, or shape: depending on origin, contents, and customer/retailer desire, there’s a whole slew of options. If you are a bartender, homebrewer, or avid consumer, it pays to know what you’re looking at.
Most kegs are made from metal–steel, or sometimes aluminum in older products. They’re fairly lightweight and easily cleaned and sanitized to use many times. They are a reusable and thus sustainable packaging. They are designed to withstand a lot of wear and tear, but they can become dented or otherwise damaged over time, especially by delivery drivers or warehouse workers who have to move them in and out of trucks and vans.
Today we also have plastic kegs as an option. Some, like those made by EcoDRAFT in Belgium can come with a replaceable internal plastic liner for reuse. Others, like PUBKEGS and those made by KeyKeg are entirely disposable vessels. These are great options for breweries sending their product a long distance (overseas, perhaps) where reclaiming their keg would be difficult or costly. Keg loss is a real financial challenge for breweries of all sizes. Kegs are expensive to replace, and it’s common to lose quite a number over a year’s time due to negligent distributors, theft, unreturned renters, confused drivers or general wear and tear. This is why you pay a hefty deposit when buying a keg of beer from a bar or brewery. While throwing away a keg is certainly less sustainable than reusing one, KeyKeg says their product is fully recyclable and made from 30% recycled plastics. The lighter weight of the plastic vessel also means a lighter load for transport, which can help increase efficient fuel use. There are certainly benefits.
Measurement units depend on measurement system for kegs, but here in the US we commonly call sizes by their portion of an American barrel, which is 31 gallons. Fun fact: a UK barrel is 36 gallons, but luckily they more frequently use liters to describe their fluid volume containers. Here’s a quick cheat-sheet for typical sizing you might find here in the US:
Some establishments might sell or rent even smaller formats, but they are far less common. Soda kegs, called Cornelius or “corny” kegs are widely used by homebrewers. These kegs were originally used for soda by major soft drink producers and fell into disuse with more available plastics (durable bags for syrups, usually).
For foreign/European kegs, see the following:
Coupler and Type
If the different sizes and shapes weren’t enough, there are also an array of couplers or connections atop kegs. This determines how you connect your “in” and “out” lines–gas in to push the liquid to the out line, to the tap and into your glass. Most American beer brands package their product in kegs with Sankey couplers, and there is a corresponding European Sankey version that is slightly different. Corney kegs typically have two distinct lines to connect in a ball-lock type set-up. And there are further though more rare types: German sliders, mostly used on certain German beer kegs, and old-school American golden gate style couplers, a somewhat more complicated arrangement originally used on pre-prohibition wooden vessels. Golden gates were gradually phased out in the mid-seventies, an act lead predominantly by Anheuser Bush in an east-to-west sweep of the US. As a result, some older West Coast breweries held onto their original parts far longer, some even to this day. Anchor Steam Brewing in San Francisco notably still uses the old-school couplers and they have become a defining choice for the brewery.
When renting a keg, the brewery or bottle shop should easily set you up with the correct coupler, but if you work at a bar with a variety of beers on tap or have a kegerator to set up at home, don’t assume you know which coupler you’ll need–there are many lists online that can help you out, like this one.
So! Ready to go out and grab a keg for your next event? Feeling more confident on the topic of couplers and connections? I wish you happy drinking, fellow beer-loving friends!