WORT SUGARS, YEAST SUGAR UPTAKE AND BEER QUALITY

The uptake of different sugars under brewing conditions in chemically defined media and in worts with different sugar adjuncts was studied. The brewer's yeasts grew equally rapidly on glucose and fructose. Howe ver, when both sugars were present in the same medium glucose inhibite d the utilization of fructose. Growth on maltose and especially on mal totriose was slower than on glucose or fructose. In the chemically def ined media the uptake of galactose, maltose and maltotriose was clearl y repressed by glucose, although in wort the repression was less marke d. The use of glucose or invert sugar in pilot scale production of bee r increased yeast growth, the fermentation rate and to some extent the amount of fusel oils, but did not significantly affect the quality of finished beer.