Best way to bring 6 month-old Wyeast up to proper cell count?

[Juno_Malone]

So, I've never done step starters before, and I'm unclear if it's necessary in this situation. My LHBS gives Wyeast packs away for free once they are 3-4 months past their "born-on" date. I picked up a pack of Wyeast Pacman that is ~6 months old, and I'm hoping to use it on a 5-gallon batch of ~1.070 OG in the near future. Based on the mrmalty yeast calc, a 1 gallon starter is not going to come close to getting the cell count to where it needs to be. Is there some calculator out there for planning out step starters, when my viability is super low, maybe 10% or less? Thanks!

 

[henchman24]

I've always had luck doing a step starter with old yeast. 0.5-.075l of 1.030 on a stirplate for a day or two (whenever it visually stops fermenting). Then throw it in the fridge, decant, and then make an appropriate sized starter from that.

I think those calculators are very conservative on how long yeast can survive. I've personally used packs/vials that are 8-9 months old using this method with great results.

Here is a calculator with steps:

http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/

 

[Juno_Malone]

I've always had luck doing a step starter with old yeast. 0.5-.075l of 1.030 on a stirplate for a day or two (whenever it visually stops fermenting). Then throw it in the fridge, decant, and then make an appropriate sized starter from that.

I think those calculators are very conservative on how long yeast can survive. I've personally used packs/vials that are 8-9 months old using this method with great results.

Thanks for the reply! My potential starter vessels are a half gallon growler, and a gallon Carlo Rossi wine jug. I don't have a stir plate, but when making starters I try to manually swirl every few hours when I'm at home. I think I'll give it a shot starting with a ~1.5L 1.030 starter in the growler, decant, and then big ol' ~3L 1.040 starter in the Carlo Rossi jug. Think that'll give me enough yeast to properly pitch a 1.070, 5.4 gallon batch?

EDIT: Didn't see your link there. Plugged these numbers in to the calc, and it says I should have ~250 billion cells after these two starter steps. Should be plenty, thanks!

 

[henchman24]

Yeah that should get you close enough. On your first step, you will probably see a lag starting with 1.5l, but it should be okay. Personally, I'd start with .5l, then add the extra 1l after a day. Then decant and make the big starter. It would give the yeast a bit easier time starting up. If you have yeast nutrient or hulls lying around, I'd throw some of those in the first step.

If you are going to get a bunch of these yeast packs in the future, a stir plate would be a wise investment. It makes growing old yeast so much easier.

I added in the link when I found it.

 

[dstockwell]

http://www.yeastcalculator.com/