Today in 1897, US Patent 589065 A was issued, an invention of Otto Zwietusch, for his “Method Of And Apparatus For Treating Beer.” There’s no Abstract, although in the description it includes this summary:

My invention relates to the treatment and finishing of beer and other malt liquids, and especially the impregnation thereof with carbonic-acid gas; and it consists in a new and useful method or art of accomplishing these results, as well as in the novel and useful apparatus therefor, all as will be fully set forth hereinafter and subsequently claimed.