Dry yeast after expiration date- still good?

[Turfgrass]

Like the title suggests, I have several packets of US-05 in my refrigerator from a long pause in brewing. They are roughly 1-1.5 years after the expired date. Would you trash them or have you had good luck? My plan was to use them to make a stout. What do you think? Thanks in advance.

 

[VikeMan]

Expiration dates (and "best by" dates) on yeast are IMO silly. It's not like everything lives until the expiration date and then everything dies. It's happening all along, before and after the magic date.

Dry yeast, if stored properly, dies off very slowly, but unfortunately there doesn't seem to be much in the way of death rate data/models like there is for liquid yeast . I suspect your packs of US-05 have a lot of viable cells remaining. I would consider using them, and maybe pitching about 1.25-ish times whatever your normal pitch would have been for these beers.

 

[odie]

use it... I bet just fine

 

[Barbarossa]

You can definitely do a starter a few days before brewday. You'll not only make sure that it's viable, you'll also have plenty of time to go go to the lhbs if it's not. But it most likely will be ok, and the starter will compensate for the cells that didn't make it.

 

[Steveruch]

I recently brewed a batch with a Muntons dated 11/16 that turned out fine. Properly stored dry yeast loses about 4% vitality a year.

 

[BrewnWKopperKat]

What do you think?

Buy a couple of fresh packages to have in reserve, then the old ones a try. My suspicion is that the beer will come out fine.

Starter (as mentioned by @Barbara) is an option as well.

As for "best by" dates, there were a couple of webinars last spring/summer/fall by Lallemand and Fermentis where they explain why they use these dates and what you might see when using yeast after it's "best by" date.

 

[Stavrose]

Heuy, Turfgrasss. I've had 1kg of Lalvin 1118 for almost 5 yeast. I've never put then in refrigerator, sometimes they're kept in plastic jar in dark place and most of the times the lights of the room were on for a few hours. I still use them, and I still make a good dry wine that reaches 11% from store bought juice. I hope this helps.

 

[dwhite60]

I've pitched four year old dry yeast with no problem.

 

[TheBluePhantom]

As long as you don't store hot and kill it, it is fine. I just pitched a 2018 M03 packet and it went off to a roaring start. I buy extra and store in the fridge, The M03 I got at expiration, I liked the yeast and they discontinued it. But I am still making ambers with M03 3 years later.

 

[Jayjay1976]

I'll happily pitch a pouch of yeast that is a year past date, provided I've stored it properly myself since it was fresh. If I have some yeast of questionable background, it gets dumped into a jar of 5-year old baker's yeast, of which I add a heaping teaspoon during the last five minutes of the boil to every batch I brew. Dead yeast make excellent nutrients for active yeast. Waste not, want not.
When I ferment batches of white sugar to make, ahem, "other" beers, this jar of leftovers is my go-to. Dry yeast is a terrible thing to waste.