Liquid Yeast Past Its "Best by" Date

Back in March I purchased a couple vials of “Cry Havoc” yeast and brewed one batch with one of the vials and planned another special brew for the other one, but it never happened and I subsequently forgot about the other vial. I found this old vial of cry havoc yeast in the back of my fridge and it says best if used by April 08.

I figured what the heck some of them must still be alive in there and made a 1/2 gallon starter last night. I know because the majority of the yeast is not viable I might have to step this up a couple of times before brewing, but I want to brew with this yeast this weekend. How would I go about figuring out 1) approximately how many cells were still alive in the vial 2) How many steps will I need to get this thing to ptichable level and 3)whether or not I will have enough time to get the starter to an appropriate pitch rate before Saturday Morning?

Any advice on this schedule would be appreciated.

I doubt you will need to step it up at all. I have used yeast 3-6 months past its prime quite a few times (half price at my lhbs) and never had a problem with them. Your starter should have plenty of time.

You probably know about this:
http://www.mrmalty.com/calc/calc.html
But it will probably tell you you need a 55 gallon drum of yeast slurry.

I'd say if you get activity in your starter you should be good to go.

I did the same thing - bought Cry Havoc in january, it said best by April, and I didn't get around to making a starter till 2 weeks ago.

It'll be fine, as long as you've kept it in the fridge, it should take off like a rocket. +1 to making a starter, but I wouldn't worry about making it huge. I'd do about 1200-1400mL in a 2L flask or 1/2 gallon growler. Should give it PLENTY of Oomph to take off with.

I've got my Cry Havoc in a batch of Apfelwein right now, in fact. It took off faster than the Lalvin EC-1118 did.

As far as steps, I would make a ~500mL starter first and let it ferment out. That takes us from today (Wed, noonish) to lets say Friday AM. Boil up your next round of starter wort on Thursday PM, make about 900mL worth... let it cool over night, pitch it Friday AM. It'll ferment throughout the day Fri and through the evening. I'll bet the krausen finishes dropping either Friday night or Saturday morning as you're getting ready to brew. Should be JUST fine.

menschmaschine said:

You probably know about this:
http://www.mrmalty.com/calc/calc.html
But it will probably tell you you need a 55 gallon drum of yeast slurry.

Click to expand...

Yes, but I don't know when the yeast was manufactured, just when it is "Best by". If i figure it was maufacutred on the first of March, to be used before the end of april only 10% of it is viable. The computer calculates I will need 3.55 liters of starter and 9 vials to get the starter going... So in short I find the calculations a little dubious, I was hoping some people would have some insight.

In short not good news for me I guess.

Donasay said:

Yes, but I don't know when the yeast was manufactured, just when it is "Best by". If i figure it was maufacutred on the first of March, to be used before the end of april only 10% of it is viable. The computer calculates I will need 3.55 liters of starter and 9 vials to get the starter going... So in short I find the calculations a little dubious, I was hoping some people would have some insight.

In short not good news for me I guess.

Click to expand...

Cry Havoc is White Labs, right? If so, White Labs yeasts are manufactured 4 months prior to their expiration date. Now the calculator will tell you you need 347 vials! I agree that the calculator doesn't seem practical for yeasts over a month old.

I bought some Wyeast Scottish Ale Yeast for my recent batch from LHBS that was manufactured in Nov 07. I made a starter which took 2 days to start. I pitched it just before it started to floccouate. Its chugging away quite nicely now.

I'm glad it ended up working, but I'll be checking the dates on all yeast I buy from now on!