Brewing with the Aurochs: Beer Color is Our Kind of Eye Candy


Beer is a glorious creation. It provides so much depth and complexity. Part of this mystique comes from the wide varieties of color in beer. The dark complexity of a stout is starkly different than the light, refreshing colors of a white ale. This contrast stirs the brain to provide a wide variety of memories and associations.

light and dark


One sometimes common assumption is that beers that are darker in appearance are heavier than lighter colored beers. This is not necessarily correct–beer color is primarily derived from browning reactions during the malting and roasting processes. Examples of browning reactions in food are the browning of toast (gluten-free of course) and the browning of a steak on a grill. Similarly, when heat is applied to grains for malting and roasting, they experience different changes in color and flavor. Body and mouthfeel are not necessarily correlated to color. We explored these topics in previous posts here and here.


Unfortunately, gluten-free beers are barely skimming the surface when it comes to beer color, as many beers rely heavily on extracts, which miss out on the roasting process. The roasting and kilning processes contribute color to the beer, but they also contribute a wide variety of flavors, including toast, biscuits, chocolate, coffee, caramel, and many more. As gluten-free brewers experiment more and more, we expect to see a wide variety of both colors and flavors in the gluten-free beer market shortly. The picture above shows our white ale on the right and our experiment with a darker ale on the left from our early homebrew experiments.


The following sections are mainly for the gluten-free homebrewers as a way to help them better predict the color of their finished beer. This can be a beneficial skill for homebrewers, as appearance plays an important role in the perception of beer taste. At Aurochs Brewing, we are homebrewers and beer lovers at heart and love to share the fruits of our labor with friends.

Beer color was originally determined using the Lovibond system and a series of glass slides. In 1952, the American Society of Brewing Chemists adopted the Standard Reference Method (SRM), which uses the optical spectrophotometer to measure the absorbance of specific wavelengths of light. It should be noted that beers with the same SRM measurement can have different hues because the human eye is capable of detecting multiple wavelengths; whereas the machine only detects a single wavelength. Beer judges also use color to evaluate a beer with respect to a style. This may or may not apply to gluten-free homebrewers, as the style guidelines for gluten-free are still in its infancy and competitions vary widely as to the category of entry for gluten-free beer. For example, the Great American Beer Festival basically just says no wheat, barley, and rye as the main criteria. The brewer can put down the classical style if there is one.

The color of a final beer can be estimated by multiplying the lovibond (°L) of a specific malt type by the pounds of malt in a recipe to calculate a malt color unit (MCU). This is where it gets a little tricky for the gluten-free all-grain homebrewer. It is pretty tough for most homebrewers to secure their own gluten-free malt for brewing, so for now we will stick with analyzing a extract example, similar to our example from calculating a grain bill.

In this example we had 6.43 lbs of sorghum syrup (3°L) and 0.78 lbs of D45 candi syrup (45°L) for a five gallon batch.

The estimated SRM is calculated by adding up the MCU’s from the individual ingredients and dividing by the volume of the batch.

MCU sorghum = 6.43lbs x 3L = 19.29
MCU D45 = 0.78lbs x 45 = 35.1
MCU Total = MCUsorghum + MCU D45
SRM = (MCUsorghum + MCUD45)/Volume = (19.29 + 35.1)/5 = 10.88

It should be noted that the simple linear formula only works for MCU greater than 15. For darker beers, its is best to use the Morey exponential model:

SRM = 1.49 x MCU^0.69