Jason Foster

Check out more of Jason Foster’s beer news and views at onbeer.org

When something gets better as it grows older, they say it “ages like a fine wine”. Note the saying is not “ages like a good beer”. There is a reason for that. Today I want to talk about why, in general, beer is best consumed fresh.

Much like our bodies, aging is a battle between the inevitable effects of the elements and our determination to resist them. A person who exercises regularly and takes care of their health is going to fare better in holding off the ravages of time than someone who does nothing but eat potato chips and watch television. The same goes for alcoholic beverages.

In one corner of the ring are the natural elements.  Four things conspire to break down the yumminess of beer. First is oxygen. That essential for life is also a beer thief. When oxygen comes in contact with almost any substance, it initiates a chemical reaction called “oxidation” - the oxygen steals an electron from the other molecules, causing instability. If you leave a half-eaten apple on the counter, its surface quickly turns brown. That is oxidation.

Oxygen alters beer’s flavour and aroma profile, and at extreme levels alters colour as well. Oxidation flattens out the aroma and mouthfeel, and will also generate off-flavours of wet paper, cardboard, sherry or mustiness.

The second conspirator is bacteria and wild yeast. Micro-organisms are, of course, everywhere. Beer even relies on a particular strain of microscopic life - brewing yeast. However, there are hundreds of competitors for the food and nutrients that beer offers. Modern brewing methods of sanitation and aggressive pitching of brewing yeast ensure that foreign micro-organisms stand no chance during fermentation. However no system is perfect and over time bacteria might catch a toehold. In normal circumstances this process takes months, however poor handling or inadequate sanitation at source can speed it up. Micro-organisms can create sour, medicinal, plastic, musty or barnyard flavours and aromas.

I hasten to add here that nothing harmful to human health can grow in beer. The bacteria and wild yeasts found in beer may make it taste bad, but they won’t hurt you. Only a narrow sub-range of micro-organisms can survive in the acidic, alcoholic environment of beer. So don’t worry about salmonella or e-coli from beer - can’t happen.

Third is sunlight, as I discussed in my last column. Beer in clear or green glass will quickly go skunky if exposed to sunlight or fluorescent light, creating an awful taste and smell.

Fourth we find that warm temperatures act as an evil catalyst to the other combatants. At warmer temperatures the reactions that cause beer spoilage will accelerate, causing the beer to go off more quickly.

In the other corner are the qualities of the beverage which hold off the four enemies. In normal circumstances, wine possesses more of these qualities than beer does - which is why it handles aging better.

The first is stability. Wine, coming from a single fruit, is quite stable. Beer on the other hand is a blend of a variety of ingredients, which is a more delicate balance. Many qualities of beer, such as hop aroma and crisp malt flavours, are fairly volatile and short-lived, meaning an older beer is going to lose these hard-to-hold qualities.

Second is alcohol. Alcohol is a natural preservative and anti-bacterial. Most organisms have a hard time living in alcohol (which is why we use it to disinfect cuts), which means the higher the alcohol content, the longer the shelf life. Micro-organism growth is retarded in high alcohol environments, and oxidation effects are more pleasant in alcoholic conditions (more sherry and less cardboard).

In short wine at 11-14% is more able to fight off the effects of aging, and even turn it to its advantage. Beer, at 5% normally, is more inadequately armed, and therefore falls apart more quickly. Beer also tends to have a higher level of residual sugars and proteins, which is a more friendly environment for micro-organisms.

One thing going for beer is hops, which is one of the strongest anti-oxidants known. Hops helps preserve beer and forestall staling effects, which means the hoppier the beer, the longer we can expect it to last.

So, how long can a beer last? Well in proper conditions (kept cool, out of sunlight, and properly packaged) it can survive 4-6 months. Hoppy beers can last longer. However, it remains true that beer is best fresh, within the first few weeks after bottling. That is why Pilsner-Urquell (or any other classic import) will taste best at the brewery.

And not all beer is created equal. A light lager is going to show signs of aging quicker than a robust stout. Beer with fresh yeast in it will last longer than filtered beer. And there are beers that intended for long-term cellaring. These beers, such as barley wines and Belgian strong ales, are higher in alcohol and complex in profile so that they benefit from aging. I will talk about cellaring beers in a future column.

In most cases, beer needs to be consumed sooner rather than later, which is maybe a good thing, as it gives you an excuse to pick up a fresh six-pack. Next column I will tell you how to determine the age of the beer you are buying.

This entry was posted on Sunday, April 11th, 2010 at 9:40 am and is filed under Beer 101 w/ Jason Foster. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.