Malts & Natural Preservatives
The tasty aromatic oils of the hop cone may be the most vulnerable to degradation, but hops are only one of the ingredients in beer. Let us examine the primary ingredient in beer: malts. Barley malt is where most of the flavor comes from in beer and it also contains the sugars that are turned into alcohol during fermentation. While a few ounces of hops spice the beer, barley malt is the backbone.
The core flavor of a beer comes from the malt and degrades over time. Beer with little malt flavors such as pale lagers have a crisp taste that becomes stale and grainy within months. These beers are made with pale malts and use little of it. More substantial beers have more shelf life, as there is a great deal more flavor to begin with and a variety of malts are often used. Stouts, for instance, have good shelf as they not only utilize more malt, but also malts with more flavor, like roasted barley.
Despite these differences, the vast majority of beers are designed and made to be drank fresh. When most beers hits the shelves it is ready to drink, so it makes sense that most beer should be kept refrigerated by both retailers and consumers. The number of beers that do not benefit from refrigeration makes up a small percentage of beer sales. Though few stores do, almost all beer should be refrigerated to preserve its brewery fresh taste.
It could be said that pale beers have less shelf life than dark beer, but there are many exceptions to this rule. The first exception is related to the alcohol content. With every pound of malt in a recipe, more sugars are added which ferment into beer. Alcohol is a natural preservative, so the higher the alcohol content the better the shelf life of a beer. More hops normally complement brews with more malt, and these are also natural preservatives.
This makes low alcohol beers most vulnerable to degradation and strong beers more resistant. As such, after hop-centric beer styles, refrigerator space should be allocated to lower alcohol, mildly flavored beers. Still, all normal beer should be refrigerated. Once a beer hits about eight percent alcohol it is widely considered to be strong ale and is a possible candidate to be kept at cellar temperatures. All should note that cellar temperature does not mean room temperature.
For the consumer, the refrigerator is usually the best option for storage. If refrigerator space is an issue, while not ideal, a week or two in the pantry is not going to ruin your beer. The only types of beer where temperature is immediately detrimental are the hoppy styles previously discussed. Normal beer can be stored at will, on the shelf or in the fridge with little issue, just as long as it is drank within a reasonable amount of time.
For the record, change in temperature (like from refrigeration to ambient temperature) does not harm beer and happens on many occasions during the distribution process. This is a myth in popular beer culture, and some have even suggested this skunks beer, which is impossible, as skunked beer occurs exclusively when UV light interacts with hop compounds.