mr_wibble
Beer Odd
Right, so O2.
The first time I saw it used was on a course at this place: All Gain Brewing, Boolaroo.
At the time he cooled the wort, the O2 was injected in-line (with a T-piece air-stone) as the wort went from the chiller into the fermenter. I remember that there was only a very small amount of bubbles visible in the sight-glass thing.
A bit after that I bought my O2 kit from MHB (now Brewman).
The general reading on it says to wave it around in the mix for 60 seconds. Lately I found something that said 60 seconds was a minimum, and 90-120 seconds was OK. But the Wyeast page says 60 seconds. Too much O2 can cause the yeast to stall the fermentation[1]. However I have not seen this personally. Wyeast says under-oxygenating is a much greater problem than over O2ing.
So, what do *I* do?
I set the O2 pressure such that it's producing a lot of tiny bubbles. If it gets to the point where it's bubbling up like blowing through a straw into a milkshake, I turn it down. I figure big bubbles don't have time or the surface area to dissolve well. When I get it to this point, I then stir vigorously and count in my head to 90 (but previously to 60). I get a thickish foam on the top of the wort - a lot like a kräusen.
But what do you do?
[1] http://discussions.probrewer.com/showthread.php?28004-Too-much-oxygen&s=32f81f3bacc2344d6eeeb975113e3926&p=91493#post91493 .
The first time I saw it used was on a course at this place: All Gain Brewing, Boolaroo.
At the time he cooled the wort, the O2 was injected in-line (with a T-piece air-stone) as the wort went from the chiller into the fermenter. I remember that there was only a very small amount of bubbles visible in the sight-glass thing.
A bit after that I bought my O2 kit from MHB (now Brewman).
The general reading on it says to wave it around in the mix for 60 seconds. Lately I found something that said 60 seconds was a minimum, and 90-120 seconds was OK. But the Wyeast page says 60 seconds. Too much O2 can cause the yeast to stall the fermentation[1]. However I have not seen this personally. Wyeast says under-oxygenating is a much greater problem than over O2ing.
So, what do *I* do?
I set the O2 pressure such that it's producing a lot of tiny bubbles. If it gets to the point where it's bubbling up like blowing through a straw into a milkshake, I turn it down. I figure big bubbles don't have time or the surface area to dissolve well. When I get it to this point, I then stir vigorously and count in my head to 90 (but previously to 60). I get a thickish foam on the top of the wort - a lot like a kräusen.
But what do you do?
[1] http://discussions.probrewer.com/showthread.php?28004-Too-much-oxygen&s=32f81f3bacc2344d6eeeb975113e3926&p=91493#post91493 .