Fermentis Yeast Expired - Use Anyway?

[moreb33rplz]

I'm doing an IPL w/ OG of 1.055, and I was going to pitch two packs of W-34/70. I just noticed they expired January 2015 (darn you online brew store!).

I think I'd still be good to use them, might have slightly less yeasties than usual. Any thoughts?

 

[Culbetron]

It should be fine. They would have to be really really old to not have enough viable yeast if you are pitching 2 11g packets.

 

[Calder]

I know you don't know how it was stored at the store, but when stored in the fridge, dried yeast looses about 4% viability per year, and will be good for many years past the expiration date.

I'm guessing it should be fine.

 

[m00ps]

I've used dried yeats a few months past its date. And that one 1 packet rehydrated. Youll be fine doing 2 as a precaution

 

[WoodlandBrew]

when stored in the fridge, dried yeast looses about 4% viability per year.

This sounds like a very reasonable number. Im always looking for more sources to back up rules like this. Do you have a source for this number?

To the ops question. You should be fine. Dry yeast is good 2 years out of the refrigerator, and 3 yeast in. From packages that I have purchased it seems they are labeled as best by 1 year after manufacturer.

Different yeast, but same manufacture showing the two and three year numbers:
http://www.fermentis.com/wp-content/uploads/2010/07/FT-Traditionnelle-EN.pdf

 

[Culbetron]

Plug it into Mrmalty.com, you'll find you need to go back many years to need two yeast packets.

 

[Calder]

This sounds like a very reasonable number. Im always looking for more sources to back up rules like this. Do you have a source for this number?

To the ops question. You should be fine. Dry yeast is good 2 years out of the refrigerator, and 3 yeast in. From packages that I have purchased it seems they are labeled as best by 1 year after manufacturer.

'Yeast', White/Zainasheff, P160.

At 75 F dry yeast looses about 20% per year.

At 38 F dry yeast looses about 4% per year.

 

[BigFloyd]

Plug it into Mrmalty.com, you'll find you need to go back many years to need two yeast packets.

He's brewing a 1.055 lager. 2 packets is appropriate since lager pitch rates are twice that of similar gravity ales. Lager yeast isn't just another strain, it's a completely different species.

 

[Culbetron]

He's brewing a 1.055 lager. 2 packets is appropriate since lager pitch rates are twice that of similar gravity ales. Lager yeast isn't just another strain, it's a completely different species.

Oops, I had the wrong batch size in mrmalty.

 

[Owly055]

rehydrate in cool (not cold not warm) water for the best survival rate. There is a study out there on this that determined that you get about double the number of viable cells if you pitch in a small amount of cool plain water... no sugars at all as compared to pitching into any kind of wort. The yeast packet contains everything it needs to get up and running. it's a little counter intuitive, but is seems to be accurate. I've gotten some nice lagers from 34/70


H.W.

 

[indiangoat]

Just added an old 1/2 pack of Fernentis red pack dated 6-2010 to a ale wert 1.054 OG at 75 deg F. Hope it starts. It's been kept at 35 deg for 6 years. I will let you know.