kettle souring

Kettle souring is a brewing process where souring bacteria, mainly Lactobacillus, are added to the brewing vessel (kettle) before boiling the beer. This allows the beer to develop a tart, sour flavor over a short period, usually within days. After achieving the desired level of sourness, the beer is boiled to kill the bacteria and then fermented normally. This method provides better control over the souring process, reduces contamination risks, and integrates sourness into the brewing process without needing long aging periods, resulting in a more efficient way to produce tart beers.