Improvements in the Manufacture of Extract of Hops.
Year: 1891

page_text: Date of Application, 16th Jan., 1891-Accepted, 21st Feb., 1891
Improvements in the Manufacture of Extract of Hops.
A. communication from Dr. OTTO SCHWEISSINGER, of Dresden, Chemist, and
LOUIS HOFFMANN, of Hamburg, Merchant, both in the German Empire.
I, ALFRED JULIUS BOULT, of 323, High Holborn, in the County of Middlesex,
M.I.M.E., do hereby declare the nature of this invention, and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
The subject of this invention is an extract of hops which unlike any of the
products of a similar nature hitherto known retains all the component elements of
hops which are considered valuable in the brewing industry. The process adopted
for its manufacture enables it to be obtained in a thick semi-liquid state and to
render it readily soluble in a cold temperature without the assistance of any special
means.
To attain this object the hop-dust (lupuline) is thoroughly freed from the husks
by means of suitable sieves. Separate extracts are then made both from the pure
lupuline and from the husks. For this purpose the husks are steeped in water and
the resulting liquid is evaporated in vacuo, so as to be reduced to a semi-liquid
condition. As for the lupuline it is introduced into extractors specially erected for
it and either quite cold or in a slightly heated condition treated with a mixture of
10 parts of ether and 90 parts of alcohol until entirely extracted. The proportions
of the ingredients of the said mixture may however vary according to circumstances
and even the use of pure ether or of alcohol alone may be admissible. The
lupuline extract may also wholly or partly be produced by compressing or by means
of a centrifugal machine.
The resulting solution is evaporated at the lowest temperature available and
hence an extract is obtained which is solid in the cold and becomes liquid
under the influence of heat and which is mixed in the liquid state with the
husk-extract.
The introduction of the mixture into the receptacles in which it is to be preserved
is then immediately proceeded with and after spreading a layer of carbonic acid over
the surface of the extract the receptacles are hermetically closed with a view to
preventing the oxydation of the oil of hops, and thereby enabling the extract to be
kept in a good condition for a long time.
It has been proposed before this by Boule to separate the hop-dust from the
husks and to mix the extract obtained from the latter in a dry state with the hop-
dust. The difference however between Boule's process and that herein described is
most essential both as regards the component materials and the action of the extract.
In this invention the aqueous husk-extract is not dried and therefore und ergoes no
disintegration. Besides an extract of hop dust instead of the natural article is here
employed whereby the utilization of those substances only which may prove of use
for brewing purposes is ensured while such superfluous insoluble parts of the hops
as cellulose and mineral substances are discarded, again the extract freed from all
insoluble and worthless ingredients will dissolve in a cold atmosphere without
requiring any auxiliary apparatus such as pans, boilers, sieves or the like.
Having now particularly described and ascertained the nature of the said
invention, as communicated to me by my foreign correspondents, and in what
manner the same is to be performed, I declare that what I claim is :-
A. process of manufacture of hop extract consisting in first obtaining separate
extracts from hop dust or flour (lupuline) and from the husks thereof for which

page_text: purpose the husks are treated with water and the dust or flour with ether, ether
and alcohol or other suitable agents whereupon the clear extract are practically
freed from their inherent solvents by evaporation and then mixing the residues
together substantially as described.
Dated this 16th day of January 1801
W. P. THOMPSON & BOULT,
Agents for the Applicant.