Journal of Agricultural Research 
Vol. II, No. a 
118 
the oils obtained from the hops of any one locality were compared with 
those from the same locality during these years. This procedure per¬ 
mitted an absolutely fair comparison by which similarities or differences 
in the properties of the oils could be easily followed and any fluctuations 
readily noted. 
DISTILLATION OF THE VOLATILE OILS 
The usual method of steam distillation was applied for the extraction 
of the volatile oils from the various samples of hops. The conditions of 
distillation were practically identical in all cases, each sample being 
distilled until no more oil was noticeable. From 100 to 200 pounds of 
California, Oregon, and Washington hops and from 50 to 100 pounds of 
New York and imported hops were distilled. The California hops were 
from Perkins, Cosumne, Ukiah, and Wheatland. The Oregon samples 
were from Independence, the Washington samples from Chehalis, and 
the New York samples from near Waterville. All were representative 
samples of commercial, sulphured hops. The imported hops were from 
Saaz, Bohemia. The distilling apparatus consists of a steel body, steel 
head, condenser, and receiver.** The material to be distilled was packed 
firmly in the still, to which the steel head was then securely clamped, 
after which steam was passed slowly through the material and the con¬ 
densed vapors collected in the receiver, the volatile oil separating in a 
distinct layer on the aqueous distillate. 
The yields of oil obtained from the various hops during the four suc¬ 
cessive seasons are given in Table I. 
Tablk I.— Yields of volatile oil from various hops during the years 1906 to 190Q , inclusive . 
Source of hops. 
Years. 
1906 
(cold 
storage). 
1906 
1907 
! 
i 1908 
! 
! 
1909 
Average. 
California: 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Perkins No. 1. 
0. 20 
O. 38 
0.43 
336 
Cosumne. 
•32 
.24 
.42 
• 326 
Perkins No. 2 &. 
•37 
•33 
•350 
Ukiah. 
*23 
•S 3 
.28 
•346 
Wheatland. 
. 21 
. 20 
. 44. 
. 282 
Oregon. 
O. 30 
O. 34 
. 20 
•32 
•30 
290 
New York. 
• 3 2 
. l6 
• 14 
‘IS 
. 192 
Washington. 
• 3 6 
.38 
•370 
Imported (Saaz). 
•33 
•45 
• 3 2 
•23 
. 24 
1 
• 3 10 
a A detailed description of the distilling apparatus is given in Bulletin 195 of the Bureau of Plant 
Industry (Rabat, 1910). 
& Grown at the Brewer ranch, located near Perkins, on the opposite side of the American River. 
