Description

This technical note details the formula used to estimate color and the limitations of approximating beer colors on your computer.

Color Units

BeerSmith allows you to use either Standard Reference Method (SRM) color measurement or European Brewing Convention (EBC) color measurement.  SRM (Lovibond) is used widely in the United States, but EBC is gaining in popularity in Europe.  You can select either in the Units tab of the Options command on the Tools menu.

BeerSmith uses the new formula for converting colors:

     EBC = 1.97 SRM

What about Lovibond?

Lovibond (L) color is an older color measurement system, which for all proactical purposes is identical to SRM for the average brewer.  For example a 40L crystal malt should be entered simply as 40 SRM color.

Estimating Color

BeerSmith uses the equation by Dan A. Morey to estimate beer color, which is a power equation fit to earlier more limited beer color estimating equations.  It holds for beer colors with SRM < 50.

The equation is: 

  SRM color = 1.4922 * (MCU ** 0.659)

where 

  MCU = (SRM_color * Grain_weight_lbs)/Volume_gallons

Reference: Brewing Techniques Magazine 

Color Display Limitations

In recipe view and in the preview pane, BeerSmith attempts to generate the approximate color of the beer.   Note, however, that the SRM/EBC color number is insufficient to determine the actual color.  For example, a beer with an SRM color of 5 brewed with a high proportion of Munich malt will have a decidedly red tint to it, while a beer brewed with pale and crystal malts with a 5 SRM color will appear straw colored.

In addition, computer displays and printers all have their own color limitations that prevent an exact match in all cases.

The color displayed in BeerSmith is meant to approximate, as closely as possible, most beer formulations.  To compare the colors of beer and recipe, put your beer in a tall glass against a white surface and hold it about arms length away.  Given the limitations inherent in estimating color, you may be surprised how close the estimate is to the actual beer.

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