Sometimes the beer one loves is only available on draft at a local brewery. Luckily, that doesn’t mean it’s impossible to bring home. Since the 1800s, imbibers have transported beer from pubs using a vessel known as a "growler." Centuries ago, growlers were designed to look like metal pails, but over time consumers adapted the container to resemble a large jug with a cap to better contain the brew.
But, be it pail or jug, those vessels have one big problem. When growlers are filled from a traditional draft line, oxygen enters the bottle and starts attacking the ale. Longstanding enemy to beer, oxygen kills carbonation, diminishes the flavor of hops, and imparts an overall stale taste. But, there's new technology out there aimed at extending the life of growler beer. Meet counter-pressure.
Similar to how beer is bottled on a bottling line but on a smaller scale, counter-pressure works by preventing oxygen from entering a growler as it's filled. Less oxygen means the beer stays fresh longer, sometimes up to several weeks as opposed to several days.
... counter-pressure works by inhibiting oxygen from entering a growler as it's filled.
Until now, imbibers keen on growlers most likely have had their jugs filled with beer straight from a tap. This beer transfer is commonly facilitated through a fill tube that looks like a tiny hose and is attached to a draft line from which pints are poured.
According to Jared Clark, Sensory Analyst for Ninkasi Brewing in Eugene, Oregon, when growlers are filled straight from a tap "there’s a lot of oxygen introduced that way and that breaks down the beer really quick." Oxygen first attacks the hops, which are often the first to go in a beer, and subsequently the beer can lose its flavor. "With counter-pressure you’re eliminating most of the oxygen in the growler and you’re essentially filling it how you might fill a bottle of beer as opposed to filling it how you might pour a pint of beer. It’s going to last a lot longer if stored properly," he says.
Using counter-pressure filling, first the bottle strapped into a device that resembles a time machine. It’s purged of oxygen using CO2 through a connected tank, and then the bottle is pressurized using a handle on the top of the filler, bringing it to the same pressure as the keg which holds the beer. That means once the beer starts flowing, the CO2 doesn’t escape and the oxygen stays out. When the growler is finally capped, it’s in a relatively oxygen-free environment. The end result is a jug of beer that can sometimes last several weeks, a huge improvement over the few days recommended for growlers filled via tube.
The end result is a jug of beer that can sometimes last several weeks, a huge improvement over the few days recommended for growlers filled via tube. "As people drink more and more beer and become more and more educated on beer, the counter-pressure or carbon-dioxide-purged growler filling is becoming more and more commonplace," states Clark.
Chris Creech, owner of The Glass Jug in Durham, North Carolina, opted to install a counter-pressure system in his specialty craft beer shop before it opened late last year. "It’s expensive, which is why you don’t see many of them," he says. Creech worked with a local company that builds and installs draft systems to spec out the setup he uses at his store. Made by Eastern European company Pegasus, Creech's counter-pressure device can fill a growler or spit beer into a pint glass from a traditional tap. One counter-pressure system can pour four different beers.
"The most common question is ‘What are those things?’ because they look like some sort of spaceship," says Creech of the counter-pressure system's design. "It enables us to easily hop into a conversation and talk about not only what it is but why we have them, because a lot of people don’t know any different. They didn’t know there's a better way [to fill a growler], so it gives us the opportunity to educate the consumer."
The Glass Jug displays a huge sign on the wall explaining the counter-pressure process. As customers become more beer savvy, it’s a filling method that Creech feels is likely to catch on.
"The overwhelming majority of people are filling [growlers] from the taps, because that was the first way people did it, and it’s the easiest. Now that the market is more competitive across the country you’re starting to see people do this more because it gives them an edge and the consumer can tell the difference is quality."
Will a counter-pressure-filled growler last forever? Not exactly. While the system eliminates most of the oxygen in a bottle, over time some is still likely to get in through the container’s screw cap. "If somebody built a growler that was filled on a counter-pressure line and then capped with something similar to a crimped bottle cap, then that would be comparable to a bottle," explains Clark. "Having just a general screw top, the majority of the time it’s not completely air tight. It will hold carbonation for a while, but it’s not going to hold it forever."
But, there's one surefire way to ensure growler beer stays fresh: pour yourself a glass immediately.