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View Full Version : Yeast past expiration date.



Dwhite
03-12-2012, 05:14 PM
Not a question just an observation.

Yesterday I put together a show mead with some wild blueberry honey.

After getting everything secure in the primary I started cleaning up and noticed the expiration date on the yeast package was 1/2011. This was over a year past, still started, and is merrily bubbling away. A little worried until I got home this evening and saw it working.

Yeast was 71B-1122


Need to manage my supplies better.

All the Best,
D. White

TAKeyser
03-12-2012, 05:19 PM
I think we've all run into pulling a pack out of the fridge only to find we haven't been paying attention to the dates as closely as we should.

Braxton
03-12-2012, 05:34 PM
I've used dry yeast that is past its expiration date before. I usually double my normal pitch rate when I do. But it still seems to work well. Man, I'm cheap. :rolleyes:

Chevette Girl
03-12-2012, 05:42 PM
I at least make sure it's doing something after rehydration before I pitch it, if it's not doing anything obvious I add some must as if I was making an acclimated starter...

I keep my yeast refrigerated so it probably extends their viability for at least a couple months but I do try to use everything before it expires.

I did underpitch once with a packet of yeast that was expired by a couple months and hadn't been refrigerated (the packet that came with a wine kit that took a while for me to get to, survived at least one summer in my kitchen) and it took a while to get going and wasn't as quick as most wine kit fermentations I've done but it did eventually finish where it was supposed to.

fatbloke
03-13-2012, 02:17 AM
Dry yeasts in original pack, is pretty much bomb proof.

Expiry dates are added as its considered as a food product, hence the legal device of an expiry date, for the makers CYA.

I just make a starter to confirm the yeast viability.......

hepcat
03-13-2012, 09:12 AM
...
I keep my yeast refrigerated so it probably extends their viability for at least a couple months but I do try to use everything before it expires.
Didn't know that. I should be keeping my dry yeast packs in the fridge? Right now I've got them stashed in a cool dry closet.

TAKeyser
03-13-2012, 11:04 AM
Didn't know that. I should be keeping my dry yeast packs in the fridge? Right now I've got them stashed in a cool dry closet.

Definitely keep them in the fridge. Every LHBS I've ever been to in the 4 states I've lived store them that way.

Dwhite
03-13-2012, 04:53 PM
This had been stored in the fridge.

This batch is really rockin' and rollin' too. Glad the yeast worked.

All the Best,
D. White

Braxton
03-13-2012, 05:50 PM
There is a drop off in viability with age for sure, though I think it would take a long time to be completely dead if it were kept refrigerated. One of the yeast manufacturers has some handy guidelines for the % drop off in viability over time, but I don't remember which one (maybe Lalvin?).