Every item added to your beer will change its color slightly. Since grains are by the largest percentage, it is expected that they have the most impact on your final beer’s color.
Most grains in their unmalted and unroasted form would impart just a pale yellow color to your beer. As grains are roasted at higher temperatures for longer times, the color they add darkens considerably.
There are a few different methods this beer color is measured: SRM, EBC, Lovibond and MCU. They all have their uses in homebrewing, so lets take a look at each of them.
Conversion Calculators: Beer & Grain Color Calculators
Standard Reference Method (SRM)
The most common value used in the US to measure beer’s color is the Standard Reference Method, or SRM for short. It was developed by the American Society of Brewing Chemists in 1950 as the scientific standard for identifying beer color. It is used in the US and abroad for measuring a beer’s specific color as well as the color each individual grain adds to it. SRM is calculated in laboratories using specialized equipment by passing light through a small sample of beer and recording the drop in intensity due to absorption.
European Beer Color (EBC)
The EBC method (European Beer Color) is the European equivalent standard to the SRM scale in Europe. Both SRM and EBC use very similar laboratory techniques to measure the beer color. Because of this similarity, SRM and EBC have an exact linear relationship to their values. In fact, the EBC value for a given grain is always a little less than double the SRM value.
In practice the EBC color is approximately 1.97 times the SRM color:
EBC = (1.97 * SRM)
The reverse calculation to convert EBC to SRM is:
SRM = (EBC / 1.97)
Lovibond is an older yet still common method for measuring the color of beer. It works by visually comparing a sample against a kit of reference colors with known values on the Lovibond scale. The Lovibond scale has mostly been replaced by the SRM and EBC methods in their respective countries for measuring beer color. However, it is still commonly used on packaging and online stores for reporting the color of malt and other brewing ingredients. The degrees Lovibond for lighter colored beers is roughly the same as the SRM value, but this does not scale up for darker beers.
The formula to convert SRM to degrees Lovibond is:
Lovibond = (SRM + 0.6) / 1.35)
The reverse formula to convert degrees Lovibond to SRM is:
SRM = ((Lovibond * 1.35) - 0.6)
Malt Color Units (MCU)
Malt Color Units (MCU) is an easy way for brewers to calculate the approximate color expected in a given recipe with multiple grains and adjuncts. This is especially useful for recipes that you are making for the first time.
In order to calculate MCU of a recipe, the calculation is:
MCU = ((Grain Weight Pounds * Grain Lovibond) / Volume Gallons)
The MCU value provides a fair color estimate for beers that are very pale in color or less than 10.5 SRM. At the low end of the SRM spectrum, MCU and SRM values close enough to use the different values interchangeably. However, because light absorbance is logarithmic and not linear, the Morey equation is needed for a better estimate of color for most beers.
Quick History Lesson: In 1995, Dan Morey wrote to the publication Brewing Techniques to propose a new way of calculating MCU values without using three different linear equations, which had been the preferred way up until then. His calculation known as the “Morey Equation” has since become standard in all brewing software.
Ok, anyway…back to the story. So the Morey equation to calculate SRM from MCU looks like this:
SRM = (1.4922 * (MCU ^ 0.6859))
Calculating a Recipe’s Color
Sometimes it is better to see it in a real world example, so lets take this grain bill of a 5 gallon Oatmeal Stout and calculate the final beer’s estimated SRM value using the Morey equation.
Ok, now that we have the grain bill, lets calculate the MCU of each grain:
|Amount||Grain||Lovibond (°L)||Malt Color Units|
|10 lb.||2-Row||1.8||(10 lb. x 1.8°L) / 5 gal = 3.6 MCU|
|1.5 lb.||Oat Malt||2.5||(1.5 lb. x 2.5°L) / 5 gal = 0.75 MCU|
|1.25 lb.||Chocolate Malt||350||(1.25 lb. x 350°L) / 5 gal = 87.5 MCU|
Lastly, we apply the Morey equation to the recipe’s total MCU value:
1.4922 * (91.85 MCU ^ 0.6859) = 33.136225 SRM
For the estimated color of the finished beer, find 33 or 34 on the SRM color chart we’ve created below.
Beer Styles & Their SRM Ranges
Certain beer styles have common SRM ranges that their color should fall within. We’ve selected a handful of the most common beer styles and listed the SRM color ranges they are typically brewed at.
|Color||Color Name||SRM Range||Styles|
|Pale Straw||2-4||Pale/Lite Lager, Pilsner, Berliner Weisse, Witbier, New England IPA|
|Straw||3-6||Maibock (Helles), Blonde Ale, California Common, Kolsch, Cream Ale|
|Pale Gold||4-8||Weissbier, Lambic, Belgian Tripel|
|Deep Gold||6-12||India Pale Ale (IPA), Pale Ale|
|Pale Amber||8-16||Saison, English Pale Ale, Irish Red Ale|
|Medium Amber||10-20||English Bitter (ESB), Belgian Dubbel|
|Deep Amber||13-26||Double IPA, Biere de Garde, Altbier, Barleywine. Scotch Ale|
|Amber Brown||17-33||Amber Ale, Vienna Lager, Dark Lager, Marzen|
|Brown||20-39||Bock, Dunkelweizen, Brown Ale, Brown Porter|
|Ruby Brown||24-47||Robust Porter, Dopplebock, Irish Dry Stout, Oatmeal Stout|
|Deep Brown||29-57||American Stout|
|Black||35-79||Russian Imperial Stout|
SRM Color Chart
Beer Maverick has created a chart that will show the expected beer colors based on the SRM values as defined in the above scale. This chart can be printed or saved off as needed.
Conversion Calculators: Beer & Grain Color Calculators