There has been interest in tristimulus reporting in the brewing community in recent years and the ASBC has an approved Method of Analysis for tristimulus characterization. The absorption of the sample is measured in 1 cm at 81 wavelengths separated by 5 nm starting at 380 nm and extending to 780 nm. These are converted to transmission values (by taking the antilogarithm of each absorption) and inserting the results into ASTM E-308. The reported tristimulus values are in L*a*b* color space and describe what is seen under Illuminant C (daylight) by a 10° observer when the path is 1 cm. The choice of path, illuminant, observer and color space does not represent a limitation of E-308 but rather the ASBC's need to standardize reporting.