What Constitutes Underpitching?

[StiefelHund]

I'm brewing a lager, and based on Mr Malty I need about 435 billion cells. I made a starter (intermittent shaking) and stepped it up once (shaking again, but not every hour like the first time). Based on the Brewers Friend yeast calculator I should have around that many cells (approx. 450 billion).

My question(s), since I didn't shake the second one as often, is it possible I didn't get as many new cells? Assuming I ended up with, say, 400 billion, is that a problem?

Thanks all!

 

[kombat]

400B would be fine - what was the volume of the starter? Do you have a plan to thoroughly aerate/oxygenate the wort?

 

[StiefelHund]

I did 2L, then stepped it up to 3L. I oxygenate by shaking the hell out of the carboy for a long, long time. So far, it's worked fine. I'll make sure this one is really shook, just in case.

 

[kombat]

That should be fine, but note that lagers have more demanding requirements than ales when it comes to oxygenation and yeast pitching rates. You're probably fine for this batch, but if you intend on making more lagers in the future, I'd encourage you to consider picking up an oxygenation stone and regulator, so you can oxygenate your lagers with pure oxygen. I just use the red disposable oxygen tanks from the welding section of the hardware store.

 

[StiefelHund]

I'll definitely look into it, thanks!