Today in 1865, US Patent 46973 A was issued, an invention of Samuel R. Percy and Walter S. Wells, for his “Improved Process for Obtaining a Condensed Extract of Hops.” There’s no Abstract, although in the description it includes this summary:

Our invention consists in the preparation of a condensed extract of hops, which possesses all the valuable properties of the hops, which is computed to lose about thirty-three and one-third per cent of their strength the first year, and afterward to decline more rapidly. All these and other objections are entirely obviated by our invention.

A quantity of hops is placed in an air-tight vessel, and the air is then exhausted therefrom in any of the methods ordinarily used for that purpose. Warm or cold water is then introduced, which should be kept heated by the admission of steam, and the hops allowed to steep for two or three hours. The degree of heat is not essential. We prefer that it should approach nearly to the boiling-point of water in vacuo. A small quantity of alkali or alkaline salts should be added to the water, the amount, when so used, not to exceed one pound of alkali or its equivalent of alkaline salts to I every one hundred pounds of hops. When the hops, by these means, are sufficiently digested, a vacuum is formed in a chamber communicating with the vessel in which the hops have been steeped, so that when the cooks communicating between this vessel and this receiver are opened the water and condensed steam containing the virtues of the hops pass through into the receiver, a vacuum being maintained therein sufficient to draw all the liquid from the hops. Water and steam are again and again admitted into the steeping vessel, as before described, until the hops are entirely exhausted of their properties. The fluid thus holding said properties in suspension is strained through a suitable strainer adjusted within the connecting pipe while in transition from the steeping-vessel to the receiver. When a sufficient quantity of this fluid extract of the hops, effected as above stated, is accumulated in the receiver, a vacuum evaporating-pan is ready for its reception by covering or coating its inner surface with any oily or fatty substance cerine, paraffine, &c., to prevent the extract from adhering to the pan and burning. Avaouum is then formed in this pan and the fluid extract is drawn through a pipe or tube connecting with the receiver, as fast as needed, into this vacuum, evaporating, or condensing pan. At such time, during the process of evaporating and condensing such fluid, as the operator may deem proper, a quantity of molasses, saccharine matters, or the extracted liquor of grain, whether malted or not, is to be drawn into the vacuum condenser and mixed with the fluid therein contained, amounting in quantity to about three gallons of molasses orits equivalent proportion of saccharine matter or extracted liquor of grain to every one hundred pounds of hops employed,though these proportions are by no means arbitrary. The whole is then evaporated or condensed to the consistence of very thick molasses, after which it may be taken out and put into vessels for use or transportation.