How Long Beer Will Stay Fresh In A Growler, Compared To Cans And Bottles

Growlers are a classic craft brewery staple. Before breweries began packaging their offerings, growlers were how patrons took beers home. They're 32- or 64-ounce glass jugs, meaning they hold about two or four pints, respectively. In recent years, you may not have seen a ton of growlers as your local taprooms might can their beer to-go. Still, growlers are efficient, sustainable since you can keep cleaning and reusing them, and nostalgic for longtime beer enthusiasts. With the current challenges the craft beer industry is facing, many breweries are scaling back on distribution operations to focus on being a local destination; this means reviving some traditions like growlers. Before you start utilizing these glass jugs, there are a few things to know, chief among them being how long beer lasts in them.

In your refrigerator, the growler's beer stays fresh for one to two weeks unopened — avoid keeping it at room temperature; colder temperatures delay chemical reactions that lead to off-flavors. Once you open the growler, you've got about 36 hours, but the sooner you enjoy it, the better. Compare this to canned beer, which stays fresh for one to two years when stored in your fridge or a cold, dark cellar, or bottled beer, which could be good for up to two years refrigerated. 

Growlers are all about freshness. They're best when you know you'll consume the beer within a few days.

Keeping beer fresh means warding off outside air with its bacteria, light, and oxygen. Bacteria is an obvious undesirable invader. Light is the offender for beer we refer to as "skunked": When light's UV rays interact with compounds from beer's hops, a chemical reaction occurs and creates the skunky-smelling compound. Oxygen deteriorates your beer, causing wet cardboard-like flavors — it's the reason why you shouldn't store beer at room temperature too long. One of the key reasons most craft beer comes in cans is because of how well aluminum protects the beer from all of these factors. The seal is perfect — the beer stays cool more easily and is completely blocked from light. Glass bottles can be sealed as well, but have less light-shielding power. Brown glass is ideal, followed by green; clear glass spells trouble.

Growlers are often brown glass, which is a plus. You can also buy and reuse stainless steel ones, offering great light protection. But because growlers are really just a jug you're opening and closing, there's less protection against oxygen and, eventually, bacteria. When you order one, the bartender pre-rinses it and may blast carbon dioxide into it to clear oxygen out. After filling the growler with beer, they'll seal the top and, according to your state's laws, may label it. Once you open the seal, carbon dioxide starts escaping and oxygen begins getting in, so keep your growler clean and enjoy that beer quickly.