remilard
Well-Known Member
Exactly the point of my post. The "little jostling" and the relatively little heat associated with mashing and sparging are almost certainly not enough to incite a chemical bonding between molecules. Maybe if you are aerosolizing the wort under pressure at +boiling temps you can experience the non-joy of HSA but otherwise no worries.
Lautering/sparging works precisely because the heat involved is enough to dissolve sugar into water, which is a chemical reaction.
Oxidative reactions clearly occur at much lower temperatures than used in sparging, the question is whether or not they happen very rapidly at those temperatures.
It seems that HSA is believed to be a practical problem generally by the people funding and carrying out research into the question.
There are a lot of references to Narziss on HSA but I can not get the articles and don't read German anyway. I did find this:
HOMEBREW Digest #3045 Tue 01 June 1999
Which indicates that Dave Radzanowski at Siebel believes that HSA is an issue in beers stored for an extended time under adverse circumstances. This doesn't apply to most homebrew since the people who brew enough to have beer on hand for 6 months or more tend to also have cold storage and all homebrewers at least keep the beer in a reasonably dark and cool place. However, when Gordon Strong was interviewed on brewing network he said he drove his beers to the second round of NHC because he believes in his extensive judging experience there that a lot of the beers are off due to having been shipped in the summer. Either he or someone else on the show mentioned tracking down a bottle of one of their own beers that was shipped and it was clearly worse than it had been before it left home.
So I am more or less convinced HSA is not a myth but I am willing to agree that it is not a practical problem for beer that will be stored well at all times.