What's The Difference Between Keg Beer And Cask Ales?

If you're not a big beer drinker, it's easy to assume that every kind mostly looks and tastes the same. But just like with any subject, learning more about it means digging into the smaller details. Like the difference between lagers and ales (the type of yeast), the difference in taste between light and dark beers (light beers have milder flavors), and plenty more. If you're at the point where you're wading into more behind-the-scenes information about how beer is made, you'll find that how the drink is stored after brewing can still affect its flavor. Indeed, whether the alcohol is placed in a keg or a cask before it's poured into your glass plays a large role in its taste and texture.

Keg beer and cask ales represent two distinct approaches to storing beer, with kegs being modern stainless-steel containers and casks being simple, no-frills barrels. Kegs are pressurized and decked out with valves and tubes, and they're built in a way which lets brewers artificially carbonate the beer. Meanwhile, a barrel is just a barrel. Nowadays, they're mostly made of metal, although old-school wooden barrels are still around. A cask requires the brewer to do more careful work by hand to keep the beer fresh, with the tradeoff being a strong flavor and a unique, less fizzy beer.

A beer keg is a fancy piece of machinery. A standard keg holds about 165 12-ounce beer cans worth of beer at about 15.5 gallons, although smaller versions of these exist. If you've ever been to a frat party, it's likely you've seen a smaller keg in action. There are plenty of miniature beer kegs designed for homes and parties rather than professionals.

Unlike your average barrel, a keg will have a valve and a tube on top that reaches all the way down to its bottom. When you turn the valve, the beer is pressurized into the tube and then it pours out into your waiting glass. The beer stored in a keg is already done fermenting, and now it's just being kept cold and carbonated. The valve which pressurizes the beer out of the keg uses gas to do this, and pressurized carbon dioxide is capable of artificially carbonating the beer to prevent it from going flat while it sits inside. This gives it a strong fizziness that you might be used to if you're accustomed to light beers and even sodas, which are carbonated this way. Both lagers and ales can be keg-conditioned, but lagers tend to be common keg fare, and some brewers like to prepare certain ales using casks instead.

The beer cask was invented thousands of years ago, and they vary in size from just a few gallons to massive 54-gallon vessels. Even though it's more challenging, there's a dedicated movement in the craft brewing community for "real ale," which is beer with live yeast that's been left to ferment in a cask and carbonated naturally rather than artificially. The fizzy carbon dioxide forms from the yeast which is still fermenting the beer inside the cask. It's a more gentle sort of carbonation than the soda-like fizz you'd get from keg beer. If you're not familiar with it, you might think it's nearly flat at first.

However, the flavor of cask is much richer and maltier due to the active yeast. The downside is that this ale has a much shorter lifespan before it spoils, so it's usually served pretty close to the brewery where it was made. It may not survive a trip farther away like sturdier keg beers. It's also served at the same temperature where it fermented in the cellar — around 50 to 55 degrees Fahrenheit — and it shouldn't be chilled or poured into frosted glasses like lighter beers. Fans say it's all worth it for the stronger taste, though.

How would you tell the two apart? Besides the temperature and carbonation, you can try checking whether the beer has been filtered. A filtered beer will be bright in color and nearly transparent if you try to look for it, because all of the yeast and proteins and other heavier ingredients in the beer have all been removed before serving. Typically, keg beers are filtered, especially if they're lagers, while some ales may be unfiltered. An unfiltered beer is much more hazy and difficult to see through, but it's still perfectly safe to drink despite having a shorter shelf-life. Any cask ale will be unfiltered, giving it a stronger flavor.

What sorts of beers are likely to be cask-conditioned? It's typically always ales; ales are the older style of beer compared to more recent lager. There isn't much reason why you can't cask-condition a lager, it's just very rarely done. This is because lagers lean toward less strong flavors, and so they benefit from the colder temperatures and stronger carbonation which make them more refreshing to drink (lagers also ferment at lower temperatures). Ales, on the other hand, are meant to have intense, hoppy flavors, and serving them rather flat and at warmer temperatures allows our taste buds to sample those flavors better. Using a cask is the perfect way to take advantage of that.