Today in 1964, US Patent 3123476 A was issued, an invention of Michael Edward Ash, assigned to Arthur Guinness Son and Company for his “Production of Hopped Wort.” Here’s the Abstract:
The invention relates to the hopping of wort, a stage in the brewing process which takes place prior to fermentation. The object of the hopping process is to extract from the hops and transfer to the Wort certain desirable flavouring substances particularly humulone, or substances derived therefrom, which are generally considered to provide the bitter flavour in finished beer, and which in some cases may exercise a preservative function.