For about the past 10 brews or so I have been chilling using an IC coupled with a paint mixing attachment and a power drill…starting a swirl right after boil. Although cooling times have been as quick as 10 minutes from boil to 65 degrees, I am wondering about HSA.
Now after reading Palmer’s site and some forum posts, I am a little bit worried…it sounds like there is an ongoing argument about HSA.
I haven’t tasted or smelled the “wet cardboard” in any of them as far as I can tell.
Should I be worried? (I am pretty relaxed right now…and I just sampled all 4 of the brews I have in the fridge…you know, just to make sure I wasn’t missing any off-flavors).
Short answer: HSA is largely a myth and not much of a worry at the homebrew scale/level.
Longer answer: You may want to wait until your IC drops the wort below 140*F before starting with the drill whirlpool.
Long answer: I think yours is the one portion of the brew day (post boil/pre-chill) where one should be at least aware of hot side aeration.
if your drill and attachment are submerged, and you are simply whirlpooling at a faster rate, HSA is of little concern. If you are constantly whipping air through your wort AFTER the boil, you may want to adjust your process a bit.
I was doing partial chill brewing for awhile, where I’d use my IC to get the wort down to 150 or so, dump it from the boil kettle to the fermenter (thereby aerating/oxygenating), then chill the rest of the way to pitch temp in my fermentation fridge overnight (this helps leave trub behind as you eventually rack/dump into a NEW fermenter). After doing some research, I made sure to chill below 140* before oxygenating/dumping into the fermenter. This seems to be the magic number of the point at which oxygen stops being bad and starts being ‘ok’ (!) I did notice an ever-so-slight papery flavor to my beer (that frankly could have come from other points in the process, but I don’t really notice it after changing my process).
The problem is, if you don’t plan on boiling it again, if a lot of air gets into the wort before it drops below 140*F, you can get some of the compounds that might give an oxidized/cardboardy flavor. I don’t believe people need to worry about HSA if it is pre-boil (like when lautering/sparging), as you are going to boil the $#!t out of the wort and drive off any nasty compounds.
I don’t think HSA is a myth, but I do think it’s not a huge concern if you’re careful. As was mentioned above, I’d wait to start the whirlpool until the wort has cooled down some. But even if you don’t, whirlpooling carefully without whipping air into the wort would be the thing to do.
I’m reading Palmer’s How to Brew and he says that the “generally accepted temperature cut-off” for preventing hot wort oxidation is 80 degrees. Page 72, 3rd ed.
My understanding is that affects LONG TERM stability more than anything. So if you are drinking your batches within 1-2 months of brewing them, probably even less of a concern.
I’m not sure where I got that 140* number from…perhaps the AHA forum? I will check tonight.
Like I said in the OP…I can’t perceive any off-flavors related to wet cardboard.[/quote]
This is kind of my point. There are a lot of differing opinions on this. I think its one of those things you have to draw your own conclusion on.
