Color Units Ebc (European Brewery Convention) refer to the color of a beer measured in a technical manner. Prior to the development of the EBC method, beer color was estimated qualitatively (and perhaps somewhat subjectively) by comparing colored glass plate references, rendered in a scale known as degrees Lovibond, to samples of beer. The sample beer was then designated as a certain color in Lovibond units.
where D = dilution factor of the sample and A430 = the light absorbance at 430 nanometers in a 1-cm cuvette. The EBC color system is used primarily in Europe, whereas North and South America use the Standard Reference Method (SRM) to measure beer color.
Additionally, both systems require that the beer sample be free of turbidity for an accurate color determination. The sample must be filtered if the turbidity is measured at greater than 1 EBC turbidity unit.
A typical American mass-market lager measures between 4 and 8 EBC units, whereas a dark stout may measure 100 EBC units or above.