Yeast starter oxygenation question...

[Beavdowg]

I used my new oxygenation system for the first time in my starter a couple days ago. The directions with the oxygenation kit I have said to give 10-15 seconds of O2 initially, then 10 second shots every hour for the first 4-8 hours. All I did was the initial 15 second burst. Who has time to give O2 every hour for 8 hours?

What are your recommendations for oxygenation for those of you that use it in your starters?

thanks

 

[JoeyChopps]

If your using a stir plate is that just wasted o2?

 

[Butter]

Personally, I wouldn't waste the o2 on a starter. Just swirling it every so often would work. Or definitely a stir plate. A 10-15 second shot of oxygen seems like overkill in a one liter starter.

 

[Beavdowg]

Are you saying that oxygenating the starter is a waste in a stir plate starter because the O2 will be driven off by the constant stirring? I can understand that logic, however, you always need to oxygenate your starter wort whether you use the shaking method or inject O2. I would think that injected O2 would be better as far as O2 concentration than just shaking the flask. Interesting questions here though.

 

[El_Exorcisto]

But using a stirplate will drive off the injected O2 and keep the starter at atmospheric O2 levels throughout it's fermentation since there is no airlock and constant agitation. Oxygenation is for primary fermentation when the environment becomes oxygen limited due to an airlock and lack of agitation.

 

[Butter]

What I meant is using a stir plate would be more effective than a single shot of O2 IMO. Plus you just put it on the stir plate and walk away.

 

[NordeastBrewer77]

What I meant is using a stir plate would be more effective than a single shot of O2 IMO. Plus you just put it on the stir plate and walk away.

exactly. the point of not air locking a starter and swirling or stir plating it is to allow the yeast to breathe during the reproduction that goes on in a starter.

 

[bovineblitz]

If your using a stir plate is that just wasted o2?

Yes.

A stir plate is better than O2 injections for a starter. It's the best way to constantly provide O2. Doing both won't be beneficial, it'll just waste O2.

 

[JoeyChopps]

Yes.

A stir plate is better than O2 injections for a starter. It's the best way to constantly provide O2. Doing both won't be beneficial, it'll just waste O2.

Right on I got a stir plate that's working awesome

 

[masampson]

However, if I'm not using a stir plate and only swirling every once in a while, would a boost of straight 02 be more beneficial than just an initial aeration by shaking/air pump?

 

[allentwnguy]

The stir plate, by the constant stirring and vortex keeps the oxygen levels up in the starter. The need for oxygenation for your wort is because the boiling process depleats the oxygen level of the wort. Oxygen is needed by the yeast in the first phase of growth. Yeast can grow with or without oxygen. With oxygenated wort the yeast can concentrate on growing and maintaining is cells. It doesn't produce much waste (alcohol and CO2) it multiplies fast and efficient. When it goes anaerobic (oxygen is gone) it uses the sugars to grow. The process is slower and it produces more waste (alcohol) but not as much cell growth as with oxygen. That's a short version.