[wsoublo]

I'm using a few guides to help prepare my answers for all possible technical questions on the BJCP written exam.

I keep seeing sulfate ion listed as improving iso-alpha acid extraction in one of the guides.  However, the guide doesn't provide any reference or mechanism description.  Also, I can't find any mechanism to explain the improved extraction on Google.  I did find a patent, but it didn't list a mechanism as far as I could tell.

I understand that sulfate lends a dryness to beer and somewhat astringent taste at higher levels, but this is different from actually increasing iso-AA solubility in wort/beer. 

Does anyone have any insight?  Thanks.

[klickitat jim]

My guess, someone is using an overly fancy term. I'll bet they are talking about SO4 enhancing pereption of bitterness.

[tschmidlin]

I'm with Jim.  I've never heard of it improving extraction.  Enhancing perception, yes.

[mabrungard]

That is a new one on me. I had not heard of sulfate improving the extraction of iso-alpha acids, but I'm not going to dismiss that it may or may not exist. I do know that sulfate helps dry the palate and that has the effect of improving the perception of bittering to the drinker.