49 replies to this topic

[positiveContact]

Who still does it and what is your method?

 

Me?

 

Any aeration that happens as the beer rushes from my garage down to the basement

And then if it's liquid yeast a minute or so of pure O2 with my flow meter set to 2.5 (LPM?? can't remember units now), dry yeast I don't pump in pure O2

 

If you don't do anything special have you done any experiments on this?  Probably someone has and I should google

[HVB]

About 2 years ago my O2 tank went empty and I never got a new one.  So about 2 years now with out any issues.

[positiveContact]

No noticable change at all?
Lag time? Attenuation? Flavor?

[djinkc]

Stir attachment on my drill. It's getting used less and less

[Big Nake]

There was talk about how oxygenation seems less necessary as people look into it more.  I think the guys on the low-O2 forum (for better or worse) still suggest it which is curious... they're "low O2" but they still want to introduce O2 when the yeast is pitched.  It was one of the first things I asked about.  I still use it on every batch and I hit my starters with some as well.  

[positiveContact]

I keep wussing out on not using it on my liquid yeast batches.  maybe the batch after this one I'll try it since I'll be pitching a pretty good slug of healthy yeast from the batch I'm making today.

[HVB]

No noticable change at all?
Lag time? Attenuation? Flavor?

Maybe it takes a bit longer but not much.  I have not noticed any issues.

 

.. they're "low O2" but they still want to introduce O2 when the yeast is pitched.  It was one of the first things I asked about.  I still use it on every batch and I hit my starters with some as well.  

 

They say it is for the yeast health at that point I believe.

[Big Nake]

They say it is for the yeast health at that point I believe.

Yes, which makes me still believe it's a good idea.  I'm not sure it's "essential" to the process but I think it's still good practice.  They also seem to believe that allowing wort to just fall into the fermenter creating some amount of O2 is okay because the yeast will use all or most of it.  Again, I'm not overly rigid on all things low-O2 but looking at it from the "low-O2" angle is unique because even though they're anti-O2, they still like the idea of it for yeast growth, health, etc.

[Bklmt2000]

Aeration stone, attached to a racking cane, and powered by an aquarium pump.

 

I let it run 10-15 minutes once the wort is in the fermenter and prior to adding the yeast.

 

I see it as good insurance that the yeast gets whatever O2 is needed for lag-phase growth, etc.

[Poptop]

Besides agitation during transport from brew area to fermentation area, nada............

[denny]

About 2 years ago my O2 tank went empty and I never got a new one.  So about 2 years now with out any issues.

 

I gave mine away because I couldn't see that it made a difference.  It was more hassle than benefit.

[denny]

I used to use a Mix Stir on every batch.  Now that I use a pump I just let the wort splash into the fermenter.  It's important to understand why you aerate and what happens.  The yeast uses the O2 to synthesize sterols, which keep cell walls flexible and encourage budding.  If you pitch proper amounts of healthy yeast, you reduce the need for cell growth, which in turn reduces the need for O2.

[HVB]

I used to use a Mix Stir on every batch.  Now that I use a pump I just let the wort splash into the fermenter.  It's important to understand why you aerate and what happens.  The yeast uses the O2 to synthesize sterols, which keep cell walls flexible and encourage budding.  If you pitch proper amounts of healthy yeast, you reduce the need for cell growth, which in turn reduces the need for O2.

I also pump into the fermenter so there is a fair amount of splashing going on.

[Bklmt2000]

I used to use a Mix Stir on every batch.  Now that I use a pump I just let the wort splash into the fermenter.  It's important to understand why you aerate and what happens.  The yeast uses the O2 to synthesize sterols, which keep cell walls flexible and encourage budding.  If you pitch proper amounts of healthy yeast, you reduce the need for cell growth, which in turn reduces the need for O2.

 

Denny, serious question: in your experience, are there any flavors or aromas that are enhanced by oxygenation before the primary ferment, or the corollary, reduced by not oxygenating?

[Big Nake]

It's important to understand why you aerate and what happens.  The yeast uses the O2 to synthesize sterols, which keep cell walls flexible and encourage budding.  If you pitch proper amounts of healthy yeast, you reduce the need for cell growth, which in turn reduces the need for O2.

It's another example that different brewers using different methods, processes and yeast strains can have different results and that ONE answer is often not enough.  I'm quite certain that there are cases where I'm underpitching and in those cases I am helped by oxygenating.  Someone else in the same circumstances but with a higher yeast cell count could get away without oxygenating and be fine. 

[Big Nake]

Denny, serious question: in your experience, are there any flavors or aromas that are enhanced by oxygenation before the primary ferment, or the corollary, reduced by not oxygenating?

Not answering for Denny but I remember reading something (this is awhile ago) that pitching a certain amount of yeast will put the yeast through various processes (growth, reproduction... I'm getting into deep water) and those processes will actually create flavors that brewers and beer-drinkers find pleasing.  When more yeast is pitched, the cells my skip those processes and those flavors will not be present.  Those words could be inaccurate, full of holes, outdated or flat-out wrong.  I just seem to remember them and I'm not sure where.  

[Bklmt2000]

Not answering for Denny but I remember reading something (this is awhile ago) that pitching a certain amount of yeast will put the yeast through various processes (growth, reproduction... I'm getting into deep water) and those processes will actually create flavors that brewers and beer-drinkers find pleasing.  When more yeast is pitched, the cells my skip those processes and those flavors will not be present.  Those words could be inaccurate, full of holes, outdated or flat-out wrong.  I just seem to remember them and I'm not sure where.  

 

Agreed, I recall hearing the same or similar, but I can't remember where anymore.

[denny]

Denny, serious question: in your experience, are there any flavors or aromas that are enhanced by oxygenation before the primary ferment, or the corollary, reduced by not oxygenating?

 

not that I recall noticing

[denny]

Not answering for Denny but I remember reading something (this is awhile ago) that pitching a certain amount of yeast will put the yeast through various processes (growth, reproduction... I'm getting into deep water) and those processes will actually create flavors that brewers and beer-drinkers find pleasing.  When more yeast is pitched, the cells my skip those processes and those flavors will not be present.  Those words could be inaccurate, full of holes, outdated or flat-out wrong.  I just seem to remember them and I'm not sure where.  

 

I learned from Dr. Clayton Cone that Acetyl co-A, an enzyme, is responsible for both cell growth and ester production. when it does one, it doesn't do the other.  So, when you pitch "too much" (yeah, vague) yeast, it doesn't require much reproduction and the enzyme goes to ester production.  Pitching less yeast means there is a need for cell growth, and there fewer esters.

[positiveContact]

my wort has something like a 9' drop before hitting the fermentor.  is this probably enough to do the job?