Beer is not only a beverage to be enjoyed but also a work of art. Its color is one of the first things that captivates our senses. From pale golden ales to deep amber lagers, beer comes in a kaleidoscope of colors. But have you ever wondered how brewers calculate the color of their brews? In this article, we will delve into the fascinating world of beer color and uncover the secret behind calculating the Standard Reference Method (SRM).
The Significance of Beer Color and SRM
Beer color is more than just an aesthetic element; it can give insights into the beer’s flavor, maltiness, and even its strength. The Standard Reference Method (SRM) is a widely-used scale used to quantify the color of beer. SRM values range from the lighter end at around 2 SRM (pale yellow) to the darker and richer hues nearing 40 SRM (deep amber or even black).
Understanding the MCU
Before we delve into calculating SRM, let’s familiarize ourselves with the Malt Color Unit (MCU). MCU is a measure of beer color that takes into account the weight of the malt used in a recipe and the volume of the beer. It is calculated using the formula MCU = (weight of malt in pounds) * (color of malt in degrees Lovibond) / (volume of beer in gallons). This calculation yields a value that indicates the color contribution of a specific malt in a certain volume of beer.
The Limitations of MCU
While MCU provides a good estimate of SRM for lighter beers, it starts to deviate as the beer color exceeds 6-8 SRM. This discrepancy arises because light absorbance is logarithmic, not linear. This means that the color gets darker at an increasing rate as the SRM value rises. To obtain a more accurate estimate for darker beers, we need to turn to the Morey equation.
Introducing the Morey Equation
The Morey equation is a mathematical formula that allows brewers to calculate SRM more accurately for a wider range of beer colors, including those that exceed 6-8 SRM. The equation is as follows: SRM color = 1.4922 * (MCU 0.6859). By utilizing this equation, brewers can obtain a more precise estimation of the SRM color value, particularly for beers with richer and deeper hues.
Applying the Morey Equation
To calculate the SRM of a beer using the Morey equation, you’ll need to determine the MCU value based on the recipe. Once you have the MCU, simply raise it to the power of 0.6859, multiply the result by 1.4922, and voila! You have the estimated SRM color of your beer. This approach accounts for the logarithmic nature of light absorbance, providing a more accurate representation of darker beer colors.
Conclusion
Calculating the SRM of a beer is a crucial step in understanding its color and overall composition. While the Malt Color Unit (MCU) gives us a decent approximation for lighter brews, the Morey equation allows brewers to obtain a more precise estimation for beers with deeper hues. By appreciating the art and science behind beer color calculation, both brewers and beer enthusiasts can deepen their understanding and enjoyment of this beloved beverage.
