If you clicked on the title of this article hoping for tips about how to make beer part of your low carbohydrate diet, I promise that you’re in for something far tastier. No, we’re not discussing low carbohydrate ale, but rather low carbonation ale.
Americans have been known to comment that beer in Britain is served warm and flat, but this is an exaggeration. First of all, if you order a pint of lager in the sceptered isle, rest assured that it will be every bit as cold and fizzy as you’ve come to expect here in the former colonies. But, if you order a pint of bitter, or any other real ale, you’ll receive 20 ounces of cellar temperature (55°F/13°C) ale that has roughly 40 percent as much carbonation as light American lagers. For sure, it’s neither super fizzy nor ice cold, but it is not warm and flat.
Ales in the United Kingdom and the Republic of Ireland are traditionally cask conditioned. This means that a dose of priming sugar is introduced into the keg (typically a 10-gallon firkin) before it is sealed with a stopper. Yeast remaining in suspension naturally carbonates the ale over a period of a few days, just as homebrewers naturally carbonate ale in bottles.
The conditioned keg is stored at cellar temperature and, when it’s time to serve, it’s vented for a few hours to reduce foaming and tapped with a faucet (for gravity pouring) or connected to a beer line for hand drawing pints with a traditional swan-necked beer engine.
Because the cask is vented to the atmosphere, dissolved carbon dioxide is free to escape until it equilibrates with the partial pressure of atmospheric carbon dioxide. And at cellar temperatures at sea level, that happens to be slightly more than one volume of carbon dioxide (note that this method also introduces oxygen, which means the entire cask must be sold within a couple of days).
To Americans raised on fizzy yellow beer, one volume is much too low: American lager would taste flat and lifeless with so little carbonation. But British styles have evolved over time to perfectly complement this style of serving, so British real ales tend to be full-bodied and rich in malt and hop flavor and aroma. Served with more carbonation and at the standard American keg temperature of 38°F (3°C), British styles can be downright insipid. But served in the traditional way, they’re sublime.
The next time you brew up an English bitter, brown porter, or oatmeal stout, try serving it the British way. If you bottle, use just one ounce of corn sugar per 5 gallons of homebrew. If you keg, set the regulator to a low 4 pounds per square inch (about 27 kilopascals or 0.25 atmospheres) and raise the temperature of your kegerator to 55°F (13°C): You may need to shorten your beverage lines to push beer at such a low pressure setting.
Serving beer this way opens up flavors and aromas that would otherwise get lost behind bubbles and frost. But be warned: British real ale can be habit forming. Perhaps that’s why so many were “sessionable” before the term was trendy!