Old yeast -- what size for starter?

[BarberSurgeon]

I've got a pack of liquid yeast that probably expired a little over a month ago. I'd still like to revive it, but not knowing how much viable yeast remain, I don't want to overwhelm them in a starter that's too large. I normally make about a liter. What do you think is an appropriate size for 4-5 month yeast?

 

[slykwilli]

One of our guys on the forums made this calc, I'd start there. http://yeastcalc.summitwoodwork.com/

 

[Misplaced_Canuck]

I've got a pack of liquid yeast that probably expired a little over a month ago. I'd still like to revive it, but not knowing how much viable yeast remain, I don't want to overwhelm them in a starter that's too large. I normally make about a liter. What do you think is an appropriate size for 4-5 month yeast?

Make a 1.030 1-Liter starter, ferment out, cold crash, decant, and do the same again.

M_C

 

[BarberSurgeon]

Well, that calculator says I should have 0% viability, but I've heard success stories, so let's give it a shot anyway!

 

[acuenca]

Well, that calculator says I should have 0% viability, but I've heard success stories, so let's give it a shot anyway!

I doubt you're at zero but you'll more than likely need to do a couple of step up starters as the post above suggested to get your numbers up...

 

[BarberSurgeon]

Starter is going now. Took a while to get going, but one more ought to be enough for a two-gallon batch!