Abstract
Colorimetric methods of estimating amino nitrogen have been calibrated, taking either glycine or leucine as the standard, and used to measure the amino nitrogen contents of worts and beers. Comparison of the 2,4,6-trinitrobenzene-1-sulphonic acid method with the ninhydrin procedure shows that amino nitrogen values differing by up to 15–20% can be obtained for the same sample and moreover that worts behave differently from beers.