20 
BULLETIN 983, U. S. DEPARTMENT OF AGRICULTURE. 
periods in the sugar solution, and, therefore, a three or four months' 
stock can usually be made up at one time. 
When a series of fermentations was ready to be run, the small yeast 
sample in either the 50 c. c. Florence flask or the side-neck Freuden- 
reich flask was added to 50 c. c. of 12° Brix sterile molasses, which was 
kept at 30° C. ±0.5° C. 35 for about 24. hours. Of this solution 10 c. c. 
was then added to 250 c. c. of 18° Brix molasses after about 18 hours 
at 30° C. Of this sample 50 e. c, was transformed to 1,500 c. c. of 18° 
Brix molasses, which was allowed to work off to about 12° Brix in 15 
to 18 hours, when it was ready for use as the starting yeast. 
Meanwhile a sprout mash was made up of 8.5 grams of malt 
sprouts and 2.5 grams of ammonium sulphate, boiled for 15 minutes 
in 250 c. c. of the wood-sugar solution to be fermented. This was 
cooled to 30° C, and 75 c. c. of the starting yeast (in 12° Brix molas- 
ses) was added. After 6 hours the mash was washed into a 20-liter 
bottle (a half carboy) with 100 c. c, of the wood-sugar solution. The 
latter varied in concentration from about 10° to 13.5° Brix, the 
average being 12° to 12.5°. The exact concentrations for each fer- 
mentation are shown on the fermentation sheet. After 3 hours 
100 c. c. of wood-sugar solution was added; after 3 hours, 200 c. c; 
after 3 hours, 200 c.c; after 2.5 hours, 400 c. c. ; and each hour there- 
after, 400 c. c, until a final volume of 2 gallons (7,570 c. c.) was made 
up. The general plan of starting and filling the fermenters is shown 
in the following table : 
Fermentation No. 
Cooks 29, 33, 34, 35, 36, 37, 38, and 
Starting yeast, 12° Brix. 
Volume 
added. 
Total 
volume. 
Volume 
added. 
Total 
volume. 
Sept. 24 
9.30 a.m. 1 ... 
C.c. 
250 
C.c. 
250 
350 
450 
650 
850 
1,250 
1,650 
2,050 
2,450 
2,850 1 
3, 250 
Sept. 25 
9.00 a. m 
10.00 a. m 
11.00 a. m 
12.00 m 
1.00 p. m 
2.00 p. m 
3.00 p. m 
4.00 p. m 
5.00 p. m 
6.00 p. m 
C.c. 
400 
400 
400 
400 
400 
. . . . ! 400 
400 
400 
400 
400 
C.c. 
3,650 
4 050 
3.30 p. m 
100 
Sept. 25 
6.30 p. m 
9.30 p. m 
12.30 a. m 
3.00 a. m 
| 100 
1 200 
1 200 
1 400 
4,450 
4,850 
5,250 
5, 650 
4.00 a. m 
5.00 a. m 
6.00 a. m 
7.00 a. m 
400 
! 400 
400 
400 
6,050 
6, 450 
6, 850 
7,250 
8.00 a. m 
400 
7.00 p. m 
320 
7,570 
i Time sprout mash was set. 
The above scheme was intended to duplicate as nearly as possible 
the times at which the different amounts of the solutions would be 
added from the different yeast tubs to the fermenters on a commercial 
scale. The first steps up to 3 a. m. are acclimating and propagating 
the yeast in the yeast tubs, and the final transfer into the fermenters 
is made at 3 a. m. From then on it takes from 12 to 18 hours in 
3 5 All fermentations were made in a fermentation room, the temperature of which was kept constant at 
30° C±0.5° C,and which could be sterilized and kept in a clean condition. 
