Authoritative Content and Methodology
Data Source and Methodology
Primary Standard: American Society of Brewing Chemists (ASBC), Method Beer-10: Beer Color (SRM), latest revision. Official standard for the SRM measurement by spectrophotometry. See: ASBC Methods of Analysis — Beer-10 (paid access) at https://www.asbcnet.org. Public overview: Beer color scale (SRM) on Wikipedia — https://en.wikipedia.org/wiki/Beer_measurement#Color
Empirical Prediction: Morey, D. (1993). The Morey color equation estimating finished beer color from MCU: SRM = 1.4922 × MCU^0.6859. A commonly accepted method summarized by Brewers Friend: https://www.brewersfriend.com/2008/04/18/srm-calculator/
Tutti i calcoli si basano rigorosamente sulle formule e sui dati forniti da questa fonte.
The Formula Explained
Glossary of Variables
- Batch size: Finished volume of beer (into fermenter), in gallons or liters.
- w (weight): Mass of each fermentable. Entered in lb or kg.
- L (Lovibond): Malt color in degrees Lovibond. If you enter EBC, we convert using L = EBC / 1.97.
- MCU: Malt Color Units = sum(weight_lb × Lovibond) / volume_gal.
- SRM: Predicted beer color using the Morey equation.
- EBC: European Brewing Convention scale. EBC ≈ 1.97 × SRM.
- HEX/RGB: On-screen color approximation derived from SRM.
How It Works: A Step‑by‑Step Example
Goal: Estimate the color of an American Amber ale.
- Units: lb and gal
- Batch size: 5.0 gal
- Fermentables: 9.0 lb Pale Malt (2 °L), 1.0 lb Crystal 60 (60 °L)
Compute MCU: MCU = \(\frac{9\times2 + 1\times60}{5} = \frac{78}{5} = 15.6\)
Apply Morey: SRM = \(1.4922 \times 15.6^{0.6859} \approx 9.8\)
Convert to EBC: EBC = \(1.97 \times 9.8 \approx 19.3\)
This yields an amber color roughly matching many style guides for American Amber and Vienna lagers. The swatch gives a visual approximation for quick comparison.
Frequently Asked Questions (FAQ)
Is SRM measured or calculated?
SRM is an optical measurement (ASBC Beer-10). This calculator predicts SRM using the grain bill (Morey equation), which closely tracks measured values for typical recipes.
Should I include specialty grains with very high color?
Yes. Include all fermentables. Very dark malts strongly affect MCU and the final SRM prediction.
What about extract or DME?
Enter extract just like grain: weight and its labeled color in Lovibond/EBC.
Why use post-boil volume?
Boil-off concentrates color. Using pre-boil volume will understate SRM.
Do mash/boil conditions change color?
Yes. Maillard reactions and caramelization can darken wort slightly. The Morey estimate is still a reliable planning tool.
Can I convert between Lovibond and EBC for malts?
This tool converts automatically using L = EBC / 1.97, which is standard for typical malts.
What accuracy should I expect?
For most recipes under ~50 SRM, predictions are usually within a few SRM units of measured values. Extremely dark or adjunct-heavy beers may deviate.