Changes

In sour beer, there might be other compounds that make the detection of DMS more difficult. For example, 2-phenylethanol and phenethyl acetate mask the perception of DMS in beer <ref name="bamforth"></ref>. Additionally, some tasters might be genetically predisposed to perceive the flavor of DMS more easily than others.

Equations have been established for estimating how much DMS will be converted from SMM during boiling, and how much SMM will be converted to DMS during cooling the wort after the boil. These equations are well explained in [http://www.amazon.com/Principles-Brewing-Science-Serious-Issues/dp/0937381748 "Principles of Brewing Science: A Study of Serious Brewing Issues", by George Fix, 1999, Pgs 89-93]. One thing to keep in mind is that the equations assume "typical" brewing practices, which include boiling the wort at some point. Because of this, the equation for how much SMM is converted to DMS during cooling may not reflect no-boil wort accurately. Let's look at some examples of the equations from "Principles of Brewing Science: A Study of Serious Brewing Issues":

We could break up the SMM conversion to DMS into many steps by measuring how much time the wort sits at the different temperatures ranges based on the [[Dimethyl_Sulfide#Mashing_and_Boiling|half-life table above]], and calculating how much SMM is converted at the different half-lives.

Yet another consideration is the effect of pH on the decomposition of SMM into DMS. The [[Dimethyl_Sulfide#Mashing_and_Boiling|half-life table above]] demonstrates that a difference of -0.3 pH increases the half-life by 5.5 minutes%. Unfortunately we do not have data to show if this effect is linear or not, but assuming it is linear then the conversion of SMM into DMS after the wort has soured would be greatly reduced. Assuming the effect of pH on SMM half-life is linear, and that every -0.3 pH is another 5.5+ minutes of half-life, the half-life table could be updated to include the first column: