Author Topic: Forced Aeration  (Read 5362 times)

horsepowerwhisperer

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Forced Aeration
« on: July 06, 2010, 11:07:59 AM »
These days, I've been using a soda keg with a sawed off dip tube as a primary fermenter.  You lose a little yield, but it sure makes transfers easy and sanitary.  Anyway, my wife is a glass blower, and she has a small O2 bottle and regulator she's willing to let me use to aerate the wort with pure O2.

I'm used to hooking up CO2 to finished kegs, setting the regulator, and shaking the keg until the gas is absorbed.  Should I expect the unfermented wort to absorb the O2 in the same way, with the fermenter sealed?  Or do I need to allow a hole for the O2 to bubble out?

Thanks for any insight!

Chris

Offline BobBrews

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Re: Forced Aeration
« Reply #1 on: July 07, 2010, 10:59:40 AM »
horsepowerwhisperer,

I think you need to drill a whole in the keg (Bail?) cover and add a airlock. I actually bought a extra cover and will use it in the refrigerator for lager beer. I think you have to let the c02 out. good luck
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Offline Dischler

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Re: Forced Aeration
« Reply #2 on: July 31, 2010, 05:25:25 AM »
The best way to aereate the wort for me has been to put a tube with a aereating stone or carbonation stone in the end.
This must of course be clean. I keep it in the wort from the bottom and let the O2 gas out in the wort. This for 3 to 6 minutes. (230 liters of wort).
This metode lets the O2 build up inside the wort and it gets quite a substansial amount of foam.
This makes the fermenting start faster and stay longer at an high level. Compared to no use of forced aeration.
I use a lid with airlock on top.

Offline MaltLicker

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Re: Forced Aeration
« Reply #3 on: July 31, 2010, 08:21:41 AM »

Chris
Aeration before pitching the yeast is different from applying CO2 to carbonate if that is your basic Q.  It's much briefer and the vessel is not yet sealed.  When aerating, we are trying to increase the dissolved O2 in PPM up to ~8-10 ppm.  When using pure O2 as Dischler describes, it takes 30 seconds to one minute, maybe two minutes for higher gravity or ten gallons. 

One key aspect with pure O2 is the type of air stone.  I think you need the smaller 0.5 micron with O2; otherwise the O2 just rushes out in big bubbles and doesn't diffuse into the wort as well.  The smaller bubbles take longer to rise, so more O2 dissolves into wort.  The larger 2.0 micron stone is for air pumps and you run those for 20-30 minutes since your using lower concentration "air" and not straight O2. 

If you're using tubing, you can create a "stiffener" out of 24" of copper wire.  Wrap the wire around a 1/4" dowel or something and it will fit nicely around the tubing, helping you get the stone to the bottom.

http://www.northernbrewer.com/default/catalogsearch/result/?q=aeration&x=0&y=0

Offline BobBrews

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Re: Forced Aeration
« Reply #4 on: August 03, 2010, 07:15:53 AM »
I use pure Oxygen. I use this from Williams Brewing. I like the Stainless Steele rod. I use it to stir while I am pumping in the O2. I also use Fermcap and I stir that into the wort. http://www.williamsbrewing.com/WILLIAM_S_OXYGEN_AERATION_SYST_P699.cfm
http://www.williamsbrewing.com/FERMCAP_FOAM_CONTROL_P1106.cfm
I don't work for Williams I bought it elsewhere but they had a easy presentation to show/
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