Shaking the starter

[yeastforbrains]

Hello fellow brewers.

I'm making a starter and I now have activity in the air lock. I figure at this point the co2 will have pushed out any oxygen not already absorbed by the wort and there will be no more oxygen in my demijohn. So continuing to shake it at this point will not really grow more yeast, will it? How?

Thanks for your input.
Yfb

 

[avidhomebrewer]

I doubt it will grow more yeast when you shake it. The yeast go through various phases during growth, absorption, etc. After you pitched the yeast, the didn't actively start fermenting. They absorbed all the O2 in the wort for the growth stage, then started fermenting.

 

[jeepinjeepin]

The more agitation you can provide (within reason) to the starter the better. Best option is a stir plate or shaker table constantly swirling the starter until you pitch. Next best would be you swirling it by hand every time you walk past it.