Craft beer is all about flavor. If your goal is to get “plastered,” there are plenty of less expensive and quicker options. You are drinking craft beer because you want more from your beer than just alcohol, but what “more” is supposed to be there and what is not?

I would encourage you to refer to columns in previous issues, found on the website, In past issues we learned that beer is not supposed to smell and taste like butter or butterscotch; a defect resulting from high levels of diacetyl. We have learned that beer is not supposed to smell and taste like corn; a defect caused by high levels of DMS (dimethyl sulfide). These two defects, unfortunately, are quite common in craft beer so knowing how to detect them is important in properly evaluating a beer.

Another common defect found in craft beer and beer in general, is staling. Beer is a perishable beverage not unlike milk. Everyone checks the date on their milk, but many folks forget that they should check the date on their beer. Unlike milk, when beer gets old, it does not get people sick. This fact leads people to believe that beer does not go bad. Nothing could be farther from the truth. The best beer is fresh beer.

Oxygen is what causes beer to stale. The aromas and flavors formed by the chemical reactions with oxygen are collectively called “oxidation.” In the brewing industry, we measure oxygen content in “parts per billion” or PPB. The standard in the beer industry for “total package oxygen” (TPO) is something less than 100 PPB. That is not very much, and the equip- ment to put beer in bottles and cans with low levels of oxygen is very expensive and beyond the reach of many small brewers. If the brewer does a poor job at limiting their dissolved oxygen (DO), the beer will be lucky to last three weeks. If they do a great job, then beer should be good for four months or maybe even six months for dark beers. Eventually, all beer will oxidize and get stale.

It is a bit easier to limit the air content of draft beer. First off, the volume of beer in the container is much greater. Kegs are filled on a closed loop system under CO2 pressure. As long as the brewer is diligent about purging the air from a keg, the DO will be limited and the beer will last longer. I’ve had plenty of oxidized beer on draft, but it is more likely that you will find oxidized beer in a bottle or can.

Hoppy beers are the first to show signs of oxidation as the hop character diminishes very quickly in the presence of oxygen. Buy a six pack of your favorite IPA. Put one bottle on top of your water heater and the rest in your refrigerator. Wait two weeks, chill the warm bottle, then taste them side by side. You should notice that the hop character of the water heater beer is muted and much less bright.

When tasting beer, the first indication of an oxidized beer will be the aroma of wet cardboard. This aroma can range from very mild to very strong in extremely oxidized beers. The next thing that you will notice is similar indications in the flavor. As the beer continues to get older and oxidize further, the rich malty flavors of fresh beer are replaced with sweet, sherry-like notes. Try the water heater experiment with your favorite malty beer, but leave it warm for closer to a month.

I hope by now you have learned to look for and drink fresh beer. With the exception of a few high gravity beers, aging does nothing but create old beer. Adopting my beer motto will enhance your beer drinking experience. Drink beer today; don’t save it for tomorrow!