Too many people associate beer color with the brew’s “strength,” by which they usually mean alcohol content, rather than depth of flavor.
The color of beer is unrelated to its alcohol content. Beer with high Alcohol by Volume (ABV) can be the palest yellow you have ever seen, likewise the blackest stout can have a low ABV. Ethyl alcohol is, after all, colorless.
What Determines Beer Color
Beer color is determined by its constituent malt or blend of malts. Beer malting involves germinating a grain, such as barley, and then cooking the grain as soon as it germinates. The grain can be roasted, the most common method of cooking the germinated grain, but it can also be baked, smoked or otherwise kilned.
No matter how it is cooked, the malt will develop a color, and the color of the cooked malt determines the color of your beer: the darker the malt is roasted the darker the color of the finished beer, just as dark roasted coffee beans produce dark coffee. Beer makers sometimes blend malts until they reach a desired color, although malts can also be manipulated for other reasons, most notably for flavor.
How to Measure Beer Color
Just as a beer’s bitterness can be measured in International Bitterness Units (IBUs), or European Bitterness Units (EBUs), the color of beer can be measured, permitting objective comparison.
Degrees Lovibond Scale
In 1883, Joseph Williams Lovibond developed the first comparative scale used in brewing called, naturally enough, the Degrees Lovibond Scale. Lovibond, a brewer, created the first colorimeter for use by brewers. Using a colorimeter, a brewer compares his beer to reference colors on glass slides. Each slide has a number. Low numbers represents a pale amber, and the higher numbers the darkest stouts and Schwarzbiers.
Standard Reference Method
The Standard Reference Method (SRM) has superseded Lovibond’s system. Whereas the Lovibond system relied upon a brewer’s eyesight to perceive color and make comparisons, SRM relies upon light spectrophotometer technology developed in the mid-twentieth century. The system measures the light that passes through a vial of beer, and the numerical readings permit ranking on a scale.
Describing the Color of Beer
To enjoy and describe beer, even hardcore hopheads have little or no need to perform anything but visual observations regarding beer color, but the brewer, from the level of advanced home through commercial megabrewery uses laboratory equipment to predict and formulate the color of the beer we get to critique, appreciate and enjoy.