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The Total Package


Beer is a complex creature. From brewhouse to warehouse, every step is vital. Yet as popular as home brewing and craft beer have become, the process of packaging beer is still littered with misconceptions, rumors and myth, and in my five years working as a packaging technician at Avery Brewing Company I’ve been asked a wide range of questions, the most frequent being: Is there really a difference in taste between kegged, bottled and canned beer? 

Simply put—yes, there are differences, and the most common culprit in varying tastes from package to package is the process of oxidation. Take imported beer for example. Customers buy a beer they’ve tried overseas and find it’s “just not the same.” There’s truth to that statement. It has to do with the distance the beer travels and the flavors that develop in the packages over time—the most notable of which is called trans-2-nonenal, basically a fancy word for oxidation. This has a flavor component with a cardboard-like taste and is created when oxygen finds its way into a finished beer. The more oxygen in the container, and the longer it sits, the more powerful this taste will become.

Imported beers are an easy example because of their overseas voyages, but oxidation can and will happen in any beer brewed anywhere in the world, including your locally brewed IPA. There’s no stopping it, only delaying it, and the greatest method of delaying this process is by packaging the beer in a CO2 heavy, oxygen-free environment.

As you can imagine, this is quite difficult, and it’s the main reason beer does in fact taste different in kegs compared to bottles and cans.

Almost all packaged beer comes from a “bright” tank—a tank containing filtered, carbonated beer that’s ready to be packaged. Oxygen, being a sly little devil, may find a way into the filtering process as well, and typically there’s a small bit of oxygen in the bright tank prior to packaging. We measure oxygen in parts per billion (ppb). Since kegs are filled directly from the bright tank to the keg itself, there’s less of a chance they’ll pick up any additional oxygen.

Think of ppb like a large pit full of one billion white ping pong balls. Within the white balls, pink balls are added to represent oxygen. If you only have five pink balls out of one billion white balls, you’re ratio is pretty low. If you have 30 pink balls, your ratio is still pretty low, but you’re chance of finding them is six times greater. The same goes for taste – you’re more likely to taste oxidation in a beer containing 30 ppb of oxygen than you are in a beer with five ppb.

Bottles and cans are entirely different beasts, and even on the most advanced packaging lines there’s still a physical gap between the filling and sealing areas where the beer is exposed to oxygen. Luckily, brewers are masters of improvisation, and they’ve been known to add zip-ties, duct tape and additional CO2 hookups to their filling areas in an effort to keep their beer fresh. Once again, though, oxygen is a fighter with great resolve, and even on our relatively advanced bottling and canning lines we tend to pick up around 30 ppb of oxygen from bright tank to package. And it’s the main reason why kegs will taste different from bottles and cans as the same batch matures in the market.

Ultimately, breweries can only do so much to combat the natural world, and packaged beer will at some point be exposed to oxygen, but the steps we as brewers take in-house can allow us to keep our beer’s flavor profiles consistent, no matter the package; and oxidized or not, as long as the consumer enjoys what they’re drinking—well, that’s all that really matters.

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