Lincoln County leader. [volume] (Toledo, Lincoln County, Or.) 1893-1987, 1911-07-21
THE CHEMISTRY OF THE HOP.

in this state makes the chemistry OF
the hop of interest both to the local
experiment station chemist as well as
as the hopgrower. The annual pro-
duction of the hop crop of this state
approximates 10000 uales annually,
while the total consumption of hops
In the United States, according to
one writer, amounts to 45,000,00O
pounds. Again, in the adoption of
proper standards for judging the. quail
ity of hops the chemical composition
must be given considerable consider
alton. Since the cone is the portion
of the plant used commercially, only
this portion will be considered in
what follows.
Many researches have been carried
out by different chemists on the COM
position of the hop cone, the earliest
investigations dating as far back as
1920. During recent years much
work has been done on this subject
and the results obtained have not
been concordant in many instances
The different investigators seem to
be agreed, however, that the principal
constituents of the hop cone are a
volatile oil, wax, hard resin, two
soft bitter resins, an alkaloid and a
tannin.
If hops are placed in a still with
water and the mixture boiled, oily
drops will be seen coming over with
the distillate. AS the process con-
tinues and a larger quantity of ma
terial collects it will be noted that
it has light green color. This oily
hop and although it amounts to only
hop and altogether it amounts to only
one-half of l per cent, it is the con-
stituent which gives to the hop it's
fragrant odor. 1t is a greenish, mo-
bile liquid and is very aromatic 1t
is composed of three or four differ
ent bodies, some of which are known
chemically as terpenes, being closely
related in composition to ordinary
turpentine.
A wax was isolated from the hop
in 1862 by German chemist. He
found the substance to be a white,
waxy material, closely allied in ma
ture to beeswax and other wakes. An
examination showed the" hop wax to
be chemical compound, known as
myricyl palmitate. The amount of
| this substance present in the hop
amounts to approximately 040 per
| cent. 1t is tasteless, inert sub,
stance which is apparently of no
value in the practical uses of the
hop.
From the investigations made it ap-
pears that there are three distinct
resinous substances in the hop cone
and for convenience two are desIg-
mated as soft resins" while the third
4 is called the hard resin" When the
3 cone is extracted with ordinary ether,
1 all three of these resins are dis
, solved. If the ether be evaporated
from the extract obtained however,
and the resulting residue be treated
!, with light petroleum spirit, only the
soft resins pass into solution, while
: the hard resin is left behind as a
light green amorphous residue.
The hard resin is almost taste1ess.
Chemical experiments indicate that
= it is probably mixture of different
g substances and no definite results
have been obtained as to it's actual
composition. So far as is known it
has no value in the practical uses OF
the hop. The amount of hard resin
seems to increase with the age of
J. the hop and also with the use of high
g temperatures in drying.
For convenience the soft resins are
J. designated as the alpha" and the
D ''beta." According to the present
0 belief these substances are the con-
stituents which impart to the hop
cone the major part of it's actual COM
mercial value. Collectively they are
known as the "hop bitter" or "bit-
+ ter principle" and many consider the
: amount of soft resins as one of the
prime factors in judging the quality
;. of the hop. Analyses made in this
t laboratory show that Oregon hops
contain from 13 to 1S per cent OF
these materials. In the pure state
the soft resins are both crystalline
'' substances, which, although only
: sparingly soluble\i in water, are read
o lily soluble in alcohol. They impart
9 to their solutions an intensely bitter
r taste. The beta" resin is colorless,
7 while the alpha is of beautiful
a golden yellow color. When in solu-
a ton both act as weak acids toward
-, alkalies and for this reason they are
: often termed the "hop-bitter acids
! They also possess certain definite an
\ tiseptic properties.
l. Hops have long been assumed to
l. contain an alkaloid. A German chem
l. ist several years ago succeeded in
s isolating substance giving the gen.
n eral reaction of an alkaloid. Subse.
n quent investigators repeated this in
vestigation with negative results. Re.
Gently, however, an alkaloid has been
isolated which is said to closely re.
semble morphine in it's properties.
9 Practically nothing of real definite
s nature is known regarding this sub
6 stance and it is evidently present in
l. very small quantity.
A tannin is present in the bracts
and stems of the hop cone which can
a be extracted with hot water. When
:, isolated it is reddish brown powder
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