Best if used by ?

[Toecutter]

I have a vial of White Labs WLP001 Pacman yeast in my frige that has a best if used by date of 5/2013. I was going to build it up with a starter to pitch in 10 gallons of some Raging Red Ale. Do you suppose its safe , or should it be discarded after its 'Best if used by date " ?

 

[bennie1986]

I just looked up this question on their FAQ page. The best if used date is 4 months from birth. They go on to say, and I'm paraphrasing, that you are still safe to use up to 12 months but a starter is highly recommended.

 

[KepowOb]

You could check out the Mr. Malty yeast pitching calculator. You can put the date of your yeast in there and it'll calculate the viability of it, and give you the size of the starter you'll need.

 

[sfgoat]

I've used two year old liquid yeast before with a starter and it worked fine. Just do a 1-2L starter and if it takes off in that after 2-3 days then it will work.