Old yeast safe

[DeanRIowa]

I found some 4 year old yeast in the back of my refrigerator that I had been saving and I was wondering, if I do a yeast starter and by chance it gets going, would it be safe to use?

If it is safe any recommendations on starting or increasing would be appreciated.


Thank you,

Dean

 

[bpgreen]

Dry yeast or liquid yeast?

 

[DeanRIowa]

Liquid: White Labs WLP029

 

[RPh_Guy]

Yes, if it ferments a starter, it's good to go.
Try a 250-500mL starter first. Avoid temperature shock.

 

[Gnomebrewer]

Do you mean a vial, or a harvested jar of WLP029?
A vial I'd trust, I wouldn't trust a jar of harvested yeast.

 

[DeanRIowa]

It is a vial, I will do a small starter and report back on the results.

Thank you,
Dean

 

[Northern_Brewer]

Be gentle with it - let it warm up properly before pitching, and do an initial starter that's only 1.025 or so, then step up. And be paranoid about sanitation - it will be working slowly, and there's not much of it, so it will be easy for contamination to overwhelm it.

 

[Comfort_Zone]

+1 for NB's advice. I've resurrected vials of yeast that were 2-3 years out of date before. Just be patient and don't push them too hard.