The color of beer has no relation to its alcohol content. For example, Guinness, one of the most popular dark beers has an alcohol volume of 4.2%, while several light-colored Belgian beers have alcohol content of 8% or more. It is the amount of sugars the beer for the yeast to eat that determines the alcoholic strength of a beer and dark roasted grains have actually less fermentable sugar.
Imported beers are stronger than American beers
Traditionally, American beers measure their alcohol content by weight, while many other countries (across Europe and in Canada) measure by volume. The alcohol by weight figure will always appear lower than the alcohol by volume – for example, 4% ABW = 5% ABV, hence the myth creation.
Brown glass is the best color to protect beer from light, which is why most beers are bottled with it. A shortage of brown glass in Europe during the last century led to many breweries using green glass to bottle their beer and people incorrectly assumed the color indicated a better beer. Typically these green bottled imported beers are actually sold with brown bottles in their native countries.
Beer is ruined if warmed and then refrigerated
This can be true, if you do it many, many times. People think re-chilling beer will cause it to be “skunked”. Beer can be ruined by air, light and time. Temperature won’t ruin a beer unless it’s extreme. UV light though will react with the hops in the beer to create a sulfur compound that does smell like skunk, so keep your beer out of bright sunlight as it can skunk in less than a minute.
This is an unfortunate myth perpetuated by the major commercial breweries – especially for their light beers. The fact is, flavor typically diminishes when beer is served ice-cold. If you want to deaden the feeling to a body part you put ice on it, the same is true with ice cold beverages on the tongue. Ice cold beer may make for a thirst-quenching, refreshing beverage, but often bears little resemblance to traditional beer. Several beers are, in fact, best served much closer to room temperature in the cool 50 degree range and are considered undrinkable when icy cold – such as Guinness and many of the traditional English ales.
Ales are served at room temperature in the UK
This story goes back to World War II, when American GIs spent considerable time in England. Cask-conditioned (or “real”) ale is served at cellar temperature, which is in the low to mid-50s and certainly not room temperature. Just like deep red wine like a Cabernet or Merlot, darker and/or stronger beers and most typically ales taste better as they get closer to a cellar temperature.