uKeg Science #1: Oxidation

Have you ever wondered why the last sip of beer doesn’t quite taste the same as the first, or why beer from a growler doesn’t taste fresh the next day?  There are a number of reasons related to your beer's environment -- including carbonation, temperature, and also exposure to oxygen.

Preventing oxidation is an important step in the brewing process, and is also important to protecting the freshness of your beer.  Diatomic oxygen, or O2, is what we need in the air we breathe.  But while oxygen reacts with our lungs, it also likes to react with beer and wine, and is what causes a pint, growler, or bottle to “go stale”.  The air around us is composed of approximately 21% Oxygen and 79% Nitrogen.  Nitrogen is inert, but oxygen is very reactive and can wreak havoc on the quality of draft beer.

Ever notice flat flavor profiles?  Paper or cardboard taste?  Sweet honey or sherry-like tones?  Those probably weren’t part of the recipe.  Oxygen reacts with the delicate aromatic compounds that give craft beer its complex flavor that your brewer worked so hard to create.  These oxidation reactions make new compounds that affect the fresh flavors.  Higher temperatures accelerate the problem.

Professor Beer wrote a great article on the Science of what happens when your beer is exposed to oxygen.  Check out the Beer Professor’s blog post and learn a thing or two about fresh beer:

Professor Beer recommends trying your own taste test to experience the difference. You can fill both a standard growler and a uKeg with the same draft beer.  Drink one pint from the growler and one pint from the uKeg each day, and blind taste test the difference.

Fresh beer is the reason we invented the uKeg, and experiencing stale beer from a growler, that was once delicious, was what inspired us to create a better solution.  The uKeg was designed to store fresh draft beer in a beer-friendly environment, thus protecting the work your brewer put into it, and keeping oxygen out is one of the key design features.  It’s also portable and fits in your kitchen refrigerator, unlike larger kegs.

To preserve the original quality of fresh draft beer, the uKeg does three things:

  • Keeps oxygen out
  • Keeps beer cold
  • Automatically keeps beer carbonated


Cheers to fresh beer!

The GrowlerWerks Team