Today in 1874, US Patent 149046 A was issued, an invention of Peter Libber, for his “Improvement In Cooling And Preserving Beer.” There’s no Abstract, but this introduction sums it up:

This invention relates to device for cooling and preserving beer and ale and similar substances in the process of manufacture, and which is required to be kept at such a temperature as to prevent its becoming sour in the process of fermentation preparatory to being barreled; and it consists in the construction and arrangement of the cooling float or swimmer employed to regulate the temperature of the beer in the fermenting tubs, as will hereinafter be more fully explained.