VITAMIN B1 AND RIBOFLAVIN IN BREWING

Vitamin B1 has been determined in a large number of beers by the fermentation method of Schultz, Atkin and Frey which has not previously been applied to worts and beers. In general, the highest amounts were found in beers of high original gravity and in those made almost entirely from malt. Well-attenuated and unprimed beers give the highest ratio, units of B1: calories. During the brew the malt, almost the sole source of vitamin B1, yields up the vitamin to the wort, which in its turn loses most of it to the yeast. Most of the vitamin B1 results have been confirmed by the thiochrome method involving an entirely different principle, whilst the general validity of both methods was further confirmed by animal feedings tests. Determination of Riboflavin (vitamin B2) by the microbiological method of Snell and Strong has led to the following conclusions:—Riboflavin is formed during germination of barley and in growing yeast. Most of the riboflavin of the malt passes into the wort during mashing and sparging and remains in the beer, the yeast not taking out any appreciable quantity. The number of microgrms. of riboflavin per 100 ml. of beer, in general, exceeds somewhat the number of degrees of original gravity.