218 YEASTS AND MOLDS 
gain in the form of yeast protein, from adding 0.5 Ib. of ammonium chloride in a 
dough batch containing 1000 Ibs. of flour and how much protein we lose by 
deducting one-half the quantity of yeast (5 lbs. would be an average amount) 
regularly used; 0.5'lb. ammonium chloride contains 0.131 lb. nitrogen; this 
times 6.25 gives 0.82 lb. protein gained by converting the salt into albuminous 
matter. Compressed bakers’ yeast contains 27 per cent dry matter; 5 lbs. of 
yeast then contains 1.35 lbs. of dry matter, 50 per cent, or 0.68 lb. of which is 
albuminous in character. We have not only as much protein produced by the 
yeast from the ammonium salt but actually more than that lost by deducting 
half the yeast in the dough batch. The economic value of a process which can 
utilize such simple substances as sugar and ammonium salts and build there- 
from complex but useful food proteins cannot be overestimated.” 
Table XXII is taken from his work and shows clearly the effect of 
ammonium chloride on gas formation in bread. 
TaBLe XXIT 
SHOWING THE INCREASE IN GAS PRODUCTION IN DOUGH USING 
AMMONIUM CHLORIDE 
(Hoffman) 
| Dough Contain- 
Fermentation Control D ough, Difference. NE Reset Difference. 
Grams Flour 
0 110 0 110 ec 0 
05 180 80 180 80 
1.0 285 105 280 100 
1.5 390 105 390 110 
20 470 80 500 110 
2.5 570 100 640 140 
3.0 665 95 785 145 
3.5 790 125 955 170 
4.0 880 90 1105 150 
4.5 980 100 1260 155 
5.0 1080 100 1400 140 
5.5 1160 80 1520 120 
6.0 1230 70 1625 105 
Total gas in six hours 1120 ce |. ... eee ee. 1515 3 
Per cent increase due to ammonium chloride.  |.............. 35 3 
Methods for Study of Yeasts. The study of yeasts demands a pure 
culture. The securing of this pure culture is not often an easy per- 
formance. Two methods have been used and are available to micro- 
biologists at the present time. 
