Beer Color: The Relationship Between Lovibond, SRM, and EBC

Beer color often plays second fiddle (or third fiddle, for that matter) to aroma and taste. However, it is an important characteristic of that can say a lot about a beer. This article covers some of the history of the systems that have been and are currently used to measure the color of malt, wort, and beer. If you’re looking for all of the technical details, this is not the article for you. If you want the layman’s overview on the subject, you’ve come to the right place.

The Beginning – Lovibond

The original system of evaluating or quantifying the color of malt, wort, and beer was developed in the late 1800s by J.W. Lovibond, whose namesake Lovibond (degrees L) scale is still in use today. That original system used a series of glass slides of varying shades. Those slides could be combined and used to compare against samples of beer or wort. Malt colors were rated by making a mash of the malt in question and measuring its wort color. Later, this system was upgraded to the Series 52 Lovibond scale. This system simply provided individual slides or samples for each numerical Lovibond rating.

And while this system had its limitations (mainly the limitations of the human eye and general human error), it would have been “good enough” for today’s homebrewer. In fact, today, most homebrewers that even care to measure their beer’s color will usually do so with a printed sheet of colors and hold it up to a sample of their beer. This is essentially what is done for judging at homebrew competitions, as well. Us homebrewers, we’re a simple folk.

Then, Science – SRM

But then some sciencey people got together in the 1950s at the American Society of Brewing Chemists (ASBC) and decided that we needed to use some sciencey equipment to make things more precise when it comes to quantifying the color of our beer. Maybe it was because the big boys needed to make sure that our American Lagers were always that beautiful golden shade of yellow; I don’t know. But when all was said and done, we got a fancy new name, the Standard Reference Method or SRM.

For all intents and purposes, SRM and the Series 52 Lovibond are basically the same scale. When it comes to the SRM scale, scientists just found a way to shoot some light at a certain wavelength (430 nm, to be exact) at a certain amount of beer (1 cm, to be exact) in a tiny little cuvette (fancy word for the thing that holds the tiny amount of beer) and get a reading. It’s a little more complicated than that (there are words like “attenuation” and “absorption” — there’s even a little math involved), but you get the idea. Essentially, they arrive at a number that generally corresponds to the color of the beer.

Don’t Forget the Europeans – EBC

Then the Europeans felt left out and decided they would create their own system for measuring beer and wort color (or colour, as they like to spell it). They basically used the exact same method, changed the math a little bit, and arrived at a system of measurement, called EBC (European Brewery Convention). The EBC scale is roughly double the SRM scale (the exact equation is EBC = SRM x 1.97).

Today, in the US, Lovibond units are still used to quantify the color of malt and extracts, while SRM is used to quantify the color of wort and beer. Where they come together is when a brewer wants to approximate a finished beer’s color in SRM by using the color of malt and extracts in Lovibond.

Calculating Beer Color from Malt Color – The Easy Way

If you use any sort of brewing software, it should be doing this work for you based on your recipe. While not exact, these software programs and calculators are usually going to get pretty close. If you’re trying to hit a certain SRM range for a given recipe, you’ll be in the ballpark. However, you’ve probably heard the phrase, “garbage in, garbage out.” The outputs of these calculations are only as good as the inputs. Many brewing software programs and calculators will have default Lovibond values for malts and extracts. But it is important to update these with accurate Lovibond values for the malts and extracts you are using. This will ensure the most accurate estimate possible.

Now, if you’re a glutton for punishment (read: really like math), here’s how you can do the math by hand.

Calculating Beer Color from Malt Color – The Hard Way

First, calculate the Malt Color Units (MCU) of your malt.

MCU = (Lovibond of Malt x Weight of Malt in lbs) / Volume of Batch in Gallons

If using malts with different Lovibond values (and you probably are), calculate each individually and then add them together.

Next, we use the Morey equation to convert MCU to SRM. The Morey equation is considered to be one of the most accurate across the entire SRM spectrum. Although, other equations can be used.

SRM = 1.49 x MCU^0.69

Other Color Considerations

The color of your malts and extracts is not the only determining factor in the final beer color. Your boil time, heat source, hops, yeast, oxidation, and other factors can also affect the color of your beer.

So I hope that helps add some color (…you see what I did there…) to the subject of malt color and beer color and how they are related and measured. Let me know your thoughts and questions in the comments below.