Changes

Normal procedure for [[Sour_Worting|kettle souring]] techniques is to boil the wort a second time after the pH has been lowered in order to kill the ''Lactobacillus'' souring culture. The pH is lowered by adding lactic acid bacteria (fermentation by the ''Lactobacillus'' generally results in a species wort pH of around 3.0 - 3.6, at which time the wort is boiled to kill the ''Lactobacillus''), and allowing them to ferment and produce lactic acid. In this case yet another consideration is the effect of low pH on the decomposition of SMM into DMS. The [[Dimethyl_Sulfide#Mashing_and_Boiling|half-life table above]] demonstrates that a decrease of -0.3 pH increases the half-life by 5.5 minutes at 100°C. Unfortunately we do not have data to show how the much lower pH values that are achieved after souring wort will effect the half-life of SMM <ref name="Scheuren2014"></ref>, but assuming the effect is linear then the conversion of SMM into DMS during the second boil would be greatly reduced. Assuming the effect of pH on SMM half-life is linear, and that every -0.3 pH increases the half-life by 5.5 minutes at 100°C, the half-life table could hypothetically be updated to include data that looks something like what we present in the first column below. This indicates that wort boiled after souring probably does not create significant amounts of DMS from SMM.