Is Hot Side Aeration A Big Worry?
- Thread starter RobboMC
- Start date
Help Support Australia & New Zealand Homebrewing Forum:
chalky
Well-Known Member
Found it, if anybody else is interested: http://www.thebrewingnetwork.com/membersar..._hsa1-26-09.mp3
Tim F
Well-Known Member
- Joined
- 28/1/08
- Messages
- 645
- Reaction score
- 7
Funny this got bumped, I was just listening to that episode today as well. Fascinating, I recommend it if you're a beer nerd. I took some notes while I listened if anyone is interested although I'm sure I missed some stuff.
The headline I got out of it was this, from Bamforth: "I am convinced that it is not a detrimental thing to have excessive aeration upstream when it comes to flavour stability"
He talked a lot about how it can actually be a good thing to aerate your preferment wort because anything that is oxidised to form staling compounds will then be driven off by a vigorous boil and more importantly consumed by the yeast, particularly if you have a good healthy pitch and vigorous fermentation. He said that yeast does such a good job of cleaning up the staling compounds that if you filter stale beer through a column of immobilised yeast you can actually clean it up so it isn't stale any more.
He said that in terms of flavour stability overwhelmingly the biggest factor is minimising oxygen in the packaged beer and controlling storage temperature - mentioned that for every 10C increase in storage temperature you increase the rate of staling 2-3 times.
Palmer summarised (not exact quote) as: "we as brewers can look at upstream process, mash, agitation, transfer etc but if we dont get too wrapped up with those steps but instead have a healthy pitch of yeast, it will take care of almost everything we did upstream."
Bamforth also said that another solution to prevent oxidisation in finished beer is to use SO2 (eg metabisulphate) although most brewers are resistant to the idea and also if you do that without having some copper in contact with the wort you risk the yeast producing hydrogen sulphate (rotten egg smell). The copper helps bind the sulphur to avoid that.
All in all worth a listen, particularly if you're building a new brew setup. I'm sure I didn't do it justice, anyone can step in to point out stuff I misunderstood
The headline I got out of it was this, from Bamforth: "I am convinced that it is not a detrimental thing to have excessive aeration upstream when it comes to flavour stability"
He talked a lot about how it can actually be a good thing to aerate your preferment wort because anything that is oxidised to form staling compounds will then be driven off by a vigorous boil and more importantly consumed by the yeast, particularly if you have a good healthy pitch and vigorous fermentation. He said that yeast does such a good job of cleaning up the staling compounds that if you filter stale beer through a column of immobilised yeast you can actually clean it up so it isn't stale any more.
He said that in terms of flavour stability overwhelmingly the biggest factor is minimising oxygen in the packaged beer and controlling storage temperature - mentioned that for every 10C increase in storage temperature you increase the rate of staling 2-3 times.
Palmer summarised (not exact quote) as: "we as brewers can look at upstream process, mash, agitation, transfer etc but if we dont get too wrapped up with those steps but instead have a healthy pitch of yeast, it will take care of almost everything we did upstream."
Bamforth also said that another solution to prevent oxidisation in finished beer is to use SO2 (eg metabisulphate) although most brewers are resistant to the idea and also if you do that without having some copper in contact with the wort you risk the yeast producing hydrogen sulphate (rotten egg smell). The copper helps bind the sulphur to avoid that.
All in all worth a listen, particularly if you're building a new brew setup. I'm sure I didn't do it justice, anyone can step in to point out stuff I misunderstood
