How to wake yeast stored in fridge from overbuild?

[farmskis]

Hello, I have stored some yeast from a starter that I overbuilt. Now it is brew day coming up and I am wondering if I just pitch the yeast or if I “wake it up” first? I overbuilt more than enough enough yeast for a typical ale and it has only been about a month that I have had it stored in the fridge. Seems with vitality it should be enough but do I need to allow time to do another starter for this one since I am not needing build it but rather just make certain it is alive and help it get going?

 

[day_trippr]

fwiw, over the years I've come to rely upon Brew United's "Homebrew Dad's Yeast Calculator" for keeping a yeast strain going for many months using over-built starters. In this case it would provide one take on yeast viability vs that one month (according to the calculator, that's a 20% hit). If you had set aside enough "cells" an 80% viability could be plenty.

I'm uber conservative about yeast pitches as it happens after substantial $$ and effort has been invested in a 10 gallon batch, so I opt for 1M cells/ml/°P for pitch rate, and if I don't have enough yeast stored I'll delay the next brew until I run it through a starter to boost the cell count up to pitch size plus another over-build for the next round...

Cheers!

 

[mashdar]

I like a starter on anything older than a week, but I may be nuts.

If you had ~+20% extra a month ago, it's probably fine.

 

[hottpeper13]

I always make a starter from the overbuild one and then save 250ml of it for next time. I try to not let them (4 strains) sit for more then 6 mo's.

 

[Duck&BarrelBrewing]

You probably are fine but you could always use some GoFirm with it to give it an extra boost and keep those yeasties happy.

 

[Bassman2003]

I agree with the other posters. At our level, you can almost never overpitch. I would make a large starter as a month in a fridge with oxygen exposure is 30 days of death for yeast.