The German organic chemist Johann Peter Griess (1829-88), who first developed the diazotization of aryl amines (the key reaction in the synthesis of the azo dyes), and a major figure in the formation of the modern dye industry, worked for more than a quarter of a century at the brewery of Samuel Allsopp and Sons in Burton upon Trent, which, owing to the presence of several notable figures and an increase in the scientific approach to brewing, became a significant centre of scientific enquiry in the 1870s and 1880s. Unlike the other Burton brewing chemists, Griess paralleled his work at the brewery with significant contributions to the chemistry of synthetic dyes, managing to keep the two activities separate-to the extent that some of his inventions in dye chemistry were filed as patents on behalf of the German dye company BASF, without the involvement of Allsopp's. This seemingly unlikely situation can be explained partly by the very different attitudes to patent protection in Britain and in Germany combined with an apparent indifference to the significant business opportunity that the presence of a leading dye chemist presented to Allsopp's. Although his work for the brewery remained largely proprietary, Griess's discoveries in dye chemistry were exploited by the German dye industry, which quickly outpaced its British counterpart. One less well-known connection between brewing and synthetic dyes, and one that may further explain Allsopp's attitude, is the use of synthetic dyes in identifying microorganisms-the perennial preoccupation of brewers seeking to maintain yield and quality. Developments of Griess's original work continue to be applied to many areas of science and technology.
Keywords: Griess reaction; Johann Peter Griess; Samuel Allsopp and Sons Brewery, Burton upon Trent, diazotization; azo dyes.