Quantcast

New Aeration Setup

HomeBrewTalk.com - Beer, Wine, Mead, & Cider Brewing Discussion Community.

Help Support Homebrew Talk:

Bromley

Well-Known Member
Joined
Mar 8, 2007
Messages
122
Reaction score
0
Location
Greenville, MI
My brewing buddy and I just got a O2 regulator and stainless steel aeration stone setup for aerating wort. He used it for the first time last night on a couple of 1/2 gallon starters for lagers we're doing this weekend. 12 hours later they were completely flat still. Usually our starters are going well before 12 hours. He says he hit each starter with 30 seconds of O2.

Should we be worried? My only thought was that he maybe oversaturated the starters with oxygen.

And before anybody asks, yes we're sure we used the oxygen tank and not a propane or MAPP one!!! :cross:
 

TexLaw

Here's Lookin' Atcha!
Lifetime Supporter
Joined
Sep 19, 2007
Messages
3,673
Reaction score
36
Location
Houston, Texas
I've never used an oxygen system, but I understand that you cannot oversaturate your wort. Rather, using pure oxygen may lead to a slightly longer lag time (relative to straight aeration), as the yeast undergoes an extended growth phase before fermenting.

Also, are you sure your starter didn't finish within the twelve hours? That's happened to me before.


TL
 
OP
B

Bromley

Well-Known Member
Joined
Mar 8, 2007
Messages
122
Reaction score
0
Location
Greenville, MI
TexLaw said:
Also, are you sure your starter didn't finish within the twelve hours? That's happened to me before.


TL

Yeah, I asked him about that. He says there was no residue on the sides of the gallon container that you would expect from a krausen forming and falling.
 
OP
B

Bromley

Well-Known Member
Joined
Mar 8, 2007
Messages
122
Reaction score
0
Location
Greenville, MI
TexLaw said:
I've never used an oxygen system, but I understand that you cannot oversaturate your wort. Rather, using pure oxygen may lead to a slightly longer lag time (relative to straight aeration), as the yeast undergoes an extended growth phase before fermenting.


TL

That's interesting. I guess that would make sense that the little buggers would be spending all their time reproducing and will get to consuming the sugars a little later.
 

TexLaw

Here's Lookin' Atcha!
Lifetime Supporter
Joined
Sep 19, 2007
Messages
3,673
Reaction score
36
Location
Houston, Texas
Bromley said:
Yeah, I asked him about that. He says there was no residue on the sides of the gallon container that you would expect from a krausen forming and falling.
I don't often get a krausen in my starters (at least, not so much of one that I expect to see crud on the sides). Did he take a hydrometer reading or just smell it? Unfermented and fermented starters smell differently, just like anything else.


TL
 

WOP31

Well-Known Member
Joined
Feb 14, 2007
Messages
1,342
Reaction score
18
Here is a good reference for information about yeast life cycles:
http://www.wyeastlab.com/he-yeast-fundamentals.cfm


Basically you can't over oxygenate your wort, here is a small section from the Wyeast website on that.
Some yeast strains have higher oxygen requirements than others. It is generally safe to assume that you need at least 10ppm of oxygen. 10ppm will supply adequate oxygen in most situations. Over-oxygenation is generally not a concern as the yeast will use all available oxygen within 3 to 9 hours of pitching and oxygen will come out of solution during that time as well. Under-oxygenation is a much bigger concern.
The lag time would not be effected by the aeration of the wort as that is just the time it takes to acclimate to the new environment. The log phase (reproductive phase) of the yeast is when the yeast is growing, and should be consuming sugars and releasing some C02, so you should see some airlock activity.

First question is what was the gravity of the wort? You should be able to check it and see if the yeast fermented at all, if so everything is fine.
 

malkore

Well-Known Member
Joined
Jun 15, 2007
Messages
6,924
Reaction score
50
Location
Nebraska
I've heard that you can over oxygenate the wort. breathing pure O2 as a human isn't good for your lungs at all.

Also, the more oxygen you give the yeast, they longer they'll spend in the aerobic phase of their life cycle, which is when they're multiplying. they don't give off much CO2 then, but you should start seeing the yeast cake getting thicker in those starters.
 
Top