Beer Colour
How do you gauge (or estimate) beer colour? This is a key consideration especially when you are adding coloured malt into your home brew recipes. If you want to avoid overshooting and adding too much coloured malt to your grist recipe, it is useful to have a method to calculate the colour contribution of each type of malt that you are considering. It is also useful to have an idea of the likely end colour of your beer.
Colour Units EBC (European Brewery Convention) refer to the colour of a beer. Prior to the development of the EBC method, beer colour was estimated qualitatively (and perhaps somewhat subjectively) by comparing coloured glass plate references, rendered in a scale known as ‘degrees Lovibond’, to samples of beer. The sample beer was then designated as a certain colour in Lovibond units. The EBC colour system is used primarily in Europe, whereas North and South America use the Standard Reference Method (SRM) to measure beer colour. The two systems are closely related, and in fact the SRM value is about half of the corresponding EBC value.
The above chart relates the colour of beer to its SRM value. This varies from 1 for a very pale lager, up to 40 for a dark stout. The colour of a beer is a function of the malts used in the mash, and the weight of each. For instance, Maris Otter malt has an SRM value of 3, or an EBC value of 6 (i.e. a light colour); chocolate malt has an SRM value of 525, or an EBC value of 1034 (i.e. a dark colour). When you purchase malted grain, its SRM (or EBC) value will be given. The Beersmith website provides a useful table of SRM values for most grains and sugars.
The estimation of EBC colour of a beer from its malt composition is as follows:
Firstly, the Malt Colour Value (MCU) is calculated for each ingredient of the grist, as a function of the SRM value of that ingredient:
MCU = the weight (in pounds) multiplied by the SRM / the volume (in gallons) of the final batch
Once you have the MCU value for each ingredient, these are added together.
The colour value is then calculated from the Morey equation:
SRM colour = 1.4922 x (total MCU ^ 0.6859) (where ^ means ‘to the power of’)
The EBC colour is 1.97 x the SRM colour.
NOTE: This calculation only works if your beer doesn’t exceed 80 EBC.
This is quite an involved calculation, which is incorporated into the designer page.