How many yeast cells would I have...

[grathan]

If I took a Wyeast smack pack of Bohemian Lager that was dated March 2013 and activated it. Let it sit for 5-7 days until fully swelled and then put on a 2L stirred starter for 3 days at room temp?


If it matters the pack was stored in the fridge in the garage where it saw several freeze/thaw cycles but mostly was stored at 40*F.

 

[sandyeggoxj]

Theoretically, if you follow a linear reduction in viability it would be zero. But we can assume that isn't true since you apparently have activity. But 5-7 days??? I would have just pitched it into a small starter and started building it up, step by step.

The freeze cycles could be bad. I understand that the yeast cells like to burst when frozen.

 

[jahdub]

People harvest much older and worse kept yeast from the dregs of bottle conditioned beers. You should probably start with a lower volume, lower gravity starter (<500mL and <1.036) and step from there.

 

[grathan]

I should note that the 2L starter took off immediately. Much like a new viable pitch would have and fully fermented within 48 hours.

If I had to guess I would say 120 billion viable cells.