Last Updated on April 18, 2024 by Doug Hall
Understanding the SRM Beer Scale: Measuring Beer Color with Precision
When you crack open a cold beer, do you pay close attention to its color? For most beer enthusiasts, the answer is probably no. They may know whether they prefer lighter or darker brews, but the exact shade remains unimportant. However, behind the scenes, brewers have a deep appreciation for the intricacies of beer color.
I am an avid homebrewer. I do not plan to enter any competitions. My only judges are the family, friends, and neighbors who taste and offer their opinions on my offerings.
Color is just one of the 3 main characteristics of a beer to evaluate how much you may enjoy it. The other major factors are the bitterness, measured in International Bittering Units (IBUs), and the maltiness of any given beer. Some may also factor the alcohol content (ABV) as a consideration. Still, others judge a beer more by the mouthfeel, head retention, complexity of flavors, etc. You get the idea. Outside the strict parameters used by official judges at competitions, the types of beer you enjoy can be influenced by several factors. Color is one of the first impressions and therefore, important to understand.
The Impact of Ingredients on Beer Color
It’s fascinating to me to understand how much every ingredient added to your beer has the power to influence its color to some extent. Among these ingredients, grains play a particularly significant role. It makes sense since they are the major ingredient for making beer.
In their raw, unroasted state, grains tend to impart a pale yellow color to the beer. But as they undergo roasting at higher temperatures and for longer durations, their contribution darkens considerably.
Unraveling the Standard Reference Method (SRM beer scale)
To accurately measure the color of beer, the Standard Reference Method (SRM beer scale) proves to be an invaluable tool. The SRM beer scale is widely adopted in the United States and beyond for precisely this purpose. Developed by the American Society of Brewing Chemists in 1950, it stands as the scientific gold standard for beer color identification.
How SRM Beer Scale Works
Sophisticated laboratory equipment and techniques are employed to calculate the SRM of a beer sample and determine the contribution of each grain to the overall color. In this process, a small sample of beer is subjected to light, and the drop in intensity resulting from absorption is recorded and analyzed.
The SRM relies on a spectrophotometer, which measures the color of the beer sample using monochromatic light at a wavelength of 430 nanometers. A 1/2-inch cell is employed, ensuring accurate readings.
Understanding the SRM Beer Scale
The SRM scale assigns numerical values to different beer colors, allowing brewers and enthusiasts to discuss and compare shades with precision. The scale ranges from 2 to 80, with each value corresponding to a specific color intensity.
- Lighter beers, such as pilsners and lagers, are typically found around the SRM number 1 or 2 mark. These brews feature a pale and transparent appearance. The same color rating applies to the majority of the mass-produced crap most people consume.
- On the other end of the spectrum, we have dark beers like stouts and porters, which boast significantly higher SRM values. These rich, robust brews often exceed 40 on the scale, offering a much deeper and opaque hue.
Reasons for SRM Limitations
While the SRM scale technically extends up to 80, most beer descriptions and menus rarely venture beyond an SRM of 40. This limitation arises from the inherent limitations of the human eye in differentiating shades of black. A beer with a very dark brown color can appear strikingly similar to one that is pitch black, making it virtually indistinguishable from an appearance perspective.
| 1. | SRM 1-2: Pale Straw |  |
| 2. | SRM 3-4: Straw |  |
| 3. | SRM 5-6: Pale Gold |  |
| 4. | SRM 7-8: Deep Gold |  |
| 5. | SRM 9-12: Amber |  |
| 6. | SRM 13-17: Deep Amber |  |
| 7. | SRM 18-20: Copper |  |
| 8. | SRM 21-24: Deep Copper |  |
| 9. | SRM 25-30: Brown |  |
| 10. | SRM 31-40: Black |  |
Final Thoughts
Although many beer lovers may not dwell on the intricacies of beer color, brewers passionately analyze and appreciate the different shades imbued by various grains. The SRM scale serves as a vital tool in their pursuit of precision, offering a scientific standard to accurately measure and describe beer color. So, the next time you raise your glass, take a moment to appreciate the hues within—it’s a testament to the craftsmanship and artistry of brewing.
- Mango Kolsch Beer Recipe Review - May 2, 2024
- Helles Lager Beer Recipe Review - May 2, 2024
- What is the Beer Bitterness Scale? IBU Simplified - April 24, 2024