Today in 1966, US Patent 3231384 A was issued, an invention of William Ernest Parker and Francis Lloyd Rigby, assigned to Canadian Breweries Ltd., for their “Continuous Boiling and Hopping of Brewers’ Wort.” There’s no Abstract, but partway down in the description is this:
The method of the present invention generally comprises forming a continuously flowing stream of hot brewers wort, causing said stream to flow in a substantially horizontal path, continuously introducing a predetermined mass of hops to said stream, heating said flowing wort, venting said stream of undesirable volatiles above said path of flow and controlling the time flow ratio of said wort and hops as to hop said wort to desired degree, and finally continuously discharging spent and hopped wort from said stream. This may be carried out with the wort and hops flowing counter-current to one another, discharging spent hops at one end of the path and hopped wort at the other. Alternatively, it may be carried out in a co-current flow.
The method may be carried out in particularly simple apparatus which may take the form, for counter-current flow, of a substantially horizontally disposed tubular vessel with provision for introducing wort towards one end thereof and hops in the other end thereof and which includes a perforated auger moving the hops in countercurrent flow to the continuously flowing wort as to cause spent hops to discharge at one end of the apparatus and hopped wort at the other, and which is a preferred type of apparatus proposed although such counter-current flow might be achieved by apparatus of other design. For cocurrent flow, the wort is introduced at one end while the hops are introduced adjacent that end and/or selectively along the length of the vessel.