Can a starter be over-aerated?

[hotwatermusic]

This is my set up for yeast starters. I generally run the air for an hour or two. Just out curiosity I was wondering what would happen if I were to leave the air on the entire day it is on the stir plate? I know I am unlikely to go above 8ppm of O2 in solution, however would the yeast gorge themselves during the cell splitting stage? In other words, should the yeast uptake as much oxygen as necessary would they continue to uptake? I know too much oxygen in solution can be a problem, but if the yeast metabolizes the O2 can introducing more have an affect?
Continuing the logic to absurdity, If I left the pump on even after the starter wort was completely fermented, would there be any down side other than the obvious staling consequences?
To be clear, I am on a stir plate with a typical aquarium air pump running threw a hepa filter.

 

[hotwatermusic]

Not to self bump here but... I think this method could help. I am thinking if I decant the nasty staled wort off anyway, the yeast cells could be essentially pre-loaded with O2 for when they are pitched and then will split again?

 

[Invertalon]

I leave my starters on the stir plate for 24-48hrs until completely fermented out usually... Then I remove from the plate, cold crash for two days or so and then decant and pitch into the beer or another starter.

 

[Beer-lord]

Just my personal opinion and not based on science but I think aerating a starter that's on a stir plate is overkill. I can't say it will help or hurt, just that it's definitely not needed.

 

[TheMadKing]

I have a pro-brewer friend and he runs pure O2 through his starter while on a stir plate for 48 hours continuously. So based on that evidence, no.. you can't over aerate starters. The worst thing that will happen is that you make more yeast than you planned and overpitch your beer.

 

[hotwatermusic]

I have a pro-brewer friend and he runs pure O2 through his starter while on a stir plate for 48 hours continuously. So based on that evidence, no.. you can't over aerate starters. The worst thing that will happen is that you make more yeast than you planned and overpitch your beer.

Thanks, that should answer that. I guess if pure O2 isn't leading to any mutations or drift, my filtered air sure won't. I'll give it shot for 24hr. One of these days when I brew something I know well and see if there are any noticeable differences.

 

[hotwatermusic]

I have a pro-brewer friend and he runs pure O2 through his starter while on a stir plate for 48 hours continuously. So based on that evidence, no.. you can't over aerate starters. The worst thing that will happen is that you make more yeast than you planned and overpitch your beer.

Thanks, that should answer that. I guess if pure O2 isn't leading to any mutations or drift, my filtered air sure won't. I'll give it shot for 24hr. One of these days when I brew something I know well and see if there are any noticeable differences.

 

[day_trippr]

Can't imagine why anyone runs a stir plate for more than 24 hours, when
the yeast produced will ferment a full batch of beer in ~three days.
I just ran a 3 liter over-build using Conan and it hit terminal gravity in 18 hours...

Cheers!

 

[sheikyerbouti]

Just my opinion, but I've never found a need for a stir plate or oxygenation of a starter. If you get a chance, swirl it when you walk by it. I do a 2 liter for 5 gallons of ale and 4 liter for 5 gallons of lager.

 

[day_trippr]

You've never resurrected bottle dregs.

And the reproductive enhancement provided by stir-plating is undeniable...

Cheers!

 

[day_trippr]

Just my personal opinion and not based on science but I think aerating a starter that's on a stir plate is overkill. I can't say it will help or hurt, just that it's definitely not needed.

"Not needed" /= "Has No Benefit".

Cheers!

 

[hotwatermusic]

Unsubscribe.ha ha

 

[kh54s10]

Just my opinion, but I've never found a need for a stir plate or oxygenation of a starter. If you get a chance, swirl it when you walk by it. I do a 2 liter for 5 gallons of ale and 4 liter for 5 gallons of lager.

Whatever works. But that is not the best way to handle a starter.

If you used a stirplate you could probably get that 2 liter starter down to .75 or 1 liter, in a small ale. The 4 liter starter might still be too small for a lager.

You really should look at some calculators and determine the size starter you really need for a particular wort.

Besides that if you put it on a stirplate it will be done in 18-24 hours, with no swirling. With your method you should run it for 36-48 hours or more.