Homebrewers Association | AHA Forum

General Category => Yeast and Fermentation => Topic started by: Pinski on August 14, 2011, 05:10:52 PM

Title: pitch then oxygenate or oxygenate then pitch?
Post by: Pinski on August 14, 2011, 05:10:52 PM
Seems like I'm seeing instructions for both in various recipes.  Wondering if and why folks might prefer one procedure over the other. Same diff?
Title: Re: pitch then oxygenate or oxygenate then pitch?
Post by: denny on August 14, 2011, 05:12:24 PM
It makes no difference at all.  I generally pitch, then oxygenate.  Subconsciously, I think it will mix in the yeast better, even though rationally I know that doesn't matter.
Title: Re: pitch then oxygenate or oxygenate then pitch?
Post by: brontotex on August 14, 2011, 11:08:37 PM
I usually oxygenate first. But I've pitched first also. I haven't noticed any difference.
Title: Re: pitch then oxygenate or oxygenate then pitch?
Post by: dhacker on August 14, 2011, 11:24:35 PM
I've done it both ways and I really don't think it matters. The only time I would make a point to pitch then shoot the O2 to it is if you used dry yeast and sprinkled instead of re-hydrating. 

I can picture the dry yeast granules making a nest inside a nice oxygen filled foam pillow!  ;)
Title: Re: pitch then oxygenate or oxygenate then pitch?
Post by: Malticulous on August 15, 2011, 12:27:16 AM
I can't oxygenate (yet) but I aerate the best I can then pitch. Hours later I shake it again to aerate it more during the growth phase. The yeast like it.
Title: Re: pitch then oxygenate or oxygenate then pitch?
Post by: a10t2 on August 15, 2011, 03:05:45 AM
This is pure speculation, but if you're oxygenating I think there might be some benefit to pitching afterwards. It's possible that the O2 levels immediately around the stone could build to the point that they'd be toxic.
Title: Re: pitch then oxygenate or oxygenate then pitch?
Post by: dhacker on August 15, 2011, 11:57:13 AM
This is pure speculation, but if you're oxygenating I think there might be some benefit to pitching afterwards. It's possible that the O2 levels immediately around the stone could build to the point that they'd be toxic.

That line of reasoning is why I have ultimately decided to oxygenate then pitch. If you are simply aerating though, I wouldn't worry about which to do first.
Title: Re: pitch then oxygenate or oxygenate then pitch?
Post by: bonjour on August 15, 2011, 06:50:38 PM
yes




(my wife hates that, answering yes to an either or question)
but if it makes no difference --- Yes
Title: Re: pitch then oxygenate or oxygenate then pitch?
Post by: majorvices on August 15, 2011, 08:09:47 PM
This is pure speculation, but if you're oxygenating I think there might be some benefit to pitching afterwards. It's possible that the O2 levels immediately around the stone could build to the point that they'd be toxic.

This is exactly my thinking as well. If you are using pumped air it might not make any difference at all, but I like to have the oxygen already available to the yeast when I pitch them in there so I always aerate first.
Title: Re: pitch then oxygenate or oxygenate then pitch?
Post by: James Lorden on August 15, 2011, 08:56:25 PM
In the Yeast book Chris White and Jamil recommend a second dose of O2 for high gravity beers.  At this point the yeast is obviously pitched  This tells me that they either it isn't completely detrimental to add O2 to a wort that has already had yeast pitched.

Me, I always hit the O2 first since I sanitized the airstone in the carboy that I plan on using.  Pull  the airstone out and pour in the yeast at the same time... cuts down on the number of times I'm taking the top off of the carboy....