Will 8 year old yeast work?

[pipes+hose]

So I was at the grocery store (costco) a little while ago and I though 'hey, I need more yeast!' so I bought a 2 lbs vacpac. 'Its a lot but I'll use it up', I thought. Well you know how it is, a few days tun in to a week, a few weeks turn into a few months and then suddenly you're moving and can't take your equipment with you, so you give it to your brother for a few years expecting him to use it. And a few years turns into 8, and he's only put 1 wash into it (and left it in the boiler...).

My yeast was packaged in 2013 (September) and has an expiry date in 2015 (September), still vaccum packed and kept in the fridge (because he was totally going to use it) all this time. Do you guys think it will still work? Will 'cold aged' yeast become the new thing?

Anyways, I'll report back on how it goes. Interested to see if people think it will work.

[Truckinbutch]

Make a starter and try a bit of it . I wouldn't be afraid of it .

[Saltbush Bill]

I agree with Butch.....make a starter and see what happens....I've got ec1118 here that was out of date when I bought it years and years ago......it still works fine.

[still_stirrin]

… Do you guys think it will still work?

Like Butch suggests, “worth a try”. It may work, or maybe it won’t. Either way, you’ve got it, so why not try?

Personally, I’ve had dry packets of yeast older than their “best used by” date. Sometimes they will work. But sometimes they smell “dirty” or “musty” and they are slow to start and poor to flocculate. Performance is degraded as it ages beyond the “sell by” date.

But, since you’re referring to a brick of live yeast, I don’t know. How does it smell? If it still has the healthy “bready” aroma, then it probably has survived. If it smells “dry” or “like dirt”, then it may be expired. Regardless, I wouldn’t make a big ferment with it until you’ve proven it still is viable. Make a starter (or two) first. Maybe you’ve lucked out.
ss

p.s. - posted with SBB.

[NZChris]

Don't trust it.
I've been caught out by trying to make bread without proving that the out of date yeast was ok. If it is dead, you can boil it to use for nutrients.

[Toxxyc]

I'd pitch it in addition to your regular yeast as food for the new yeast. IMO there's no need to boil it first. If it's dead, it's food. If not, it ferments.

[quadra]

A sealed brick of dry yeast that has been cold stored... I would guess there may be some viable... Hell my kid would probably document making a starter from it and put it up on YouTube.
However... Why bother when you can just buy fresh and be done with it?

[Yummyrum]

Hell , I remember when Covid first hit . Couldn’t buy fresh yeast for months . All wannabe home bakers bought it out in days .

It was amazing how many out of date packs found around worked just fine .

[jonnys_spirit]

I hope she don’t boil me for food when I’m past my sell-by date and replace me with a fresh smelling batch of man. Give me a warm sponge bath and step feed me! Just need a chance! I promise i’ll make etoh!

[pipes+hose]

I won't keep your guys in suspense any longer, I tried it in a starter and it worked! Maybe not as strong as you're expect but still worked. So i threw together 18L of Rad's AllBran and it started bubbeling away nice and fast. pretty close to what I remember from long ago (scaled down since I used to wash 60L at a time).

[morefog]

Great, now make sure you keep the wash at optimal temperature. I've been fighting a stuck mash for a week and it will be good for you not to repeat some of my mistakes.

As for yeast, my open pack of very old dry distiller's yeast (DADY) was dead, but my equally old unopened bags of brewers yeast still had vitality. I didn't know the DADY was dead until my fermentation stuck. Only then did I think to make a starter with it. Dead. Then I made a starter with my equally old frozen vacuum sealed yeast and it worked, just not as well as it should have. The thing I hadn't realized is DADY and brewers yeast operate optimally at completely different temperatures, which no doubt contributed to my struggles.

Long way of saying I did some research and supposedly yeast deteriorates quickly when exposed to air. Seal what you've got up good and plan to make another batch, and another starter, soon. Good luck.

[pipes+hose]

a little update, really just to say the yeast seems to be working fine. I've got the extra that I didn't use stored in jars in the fridge.

Wash 1 (from December) was
4Kg sugar filled to 18L with 300 g bran, 0.5 tsp 24-8-16, 0.5 tsp epson salts, 1TBS boiled yeast.
It seemed to run fine but ended at 1.002 sg (after ~3 days), and got down to 1.000 after 2 weeks. I did some questionable over heating to it with my heating pad in the 22 to 44 hours area, so that might have been a problem. Or maybe too much acidity or too much alcohol percent? No mater, its a test that I'm not putting effort in to wringing the last bits of efficiency out of, I stripped it for later use. I intended to reduce alcohol percent anyways in the hopes of avoiding off tastes.

Wash 2 is
3Kg sugar filled to 16L with 200 g bran, and the same (0.5 tsp 24-8-16, 0.5 tsp epson salts, 1TBS boiled yeast).
After 63 hours its already down to 0.992. The efficiency of converting sugar to alcohol is already 10% better and the yeast are working.

[whiskymonster]

As far as i can tell the use by date isnt to do with the yeast inside but the storage qualities of the packet.

I found a couple of packets of dady in the back of the cupboard last year. Both had been opened, both over a year out of date. One was in a tupperware container and the other the top of the bag had just been rolled down and held closed with a washing peg.

The tupperware one worked just fine, but the one that was just pegged showed no activity at all.

Carlsberg reanimated yeast from a bottle over 100 years old, so it proves that if the storage is right then yeasties will wait patiently for as long as they have to.

https://www.carlsberggroup.com/pursuit- ... rom%201883.

[Demy]

Hell , I remember when Covid first hit . Couldn’t buy fresh yeast for months . All wannabe home bakers bought it out in days .

It was amazing how many out of date packs found around worked just fine .

Same thing here in Italy, yeast that disappeared in that period ... I bet that now few of those people still have "hands in the dough"

[MereCashmere]

Don't trust it.
I've been caught out by trying to make bread without proving that the out of date yeast was ok. If it is dead, you can boil it to use for nutrients.

I think this is the answer. I’ve had old yeast really mess up a batch. Think of it like you’ve got an unending supply of yeast nutrient now

[fzbwfk9r]

the only way to know is to do a small test batch

as for the longevity, archaeologists have found yeast from thousands of years ago
as long as it is kept in proper containers... dry, dark, cool, etc...

also remember reading about some researchers finding 1000yo beer at the bottom of the Mediterranean, there was yeast laying in the bottom of the bottles, they rebuilt it using fresh wort, and it worked well for them.

I keep my yeast in the freezer in a sealed dark jar. I have never had any that did not work for me.

[NormandieStill]

also remember reading about some researchers finding 1000yo beer at the bottom of the Mediterranean, there was yeast laying in the bottom of the bottles, they rebuilt it using fresh wort, and it worked well for them.

This sounds like the plot of a bad sci-fi horror film. "The Yeast From The Deep."

[fzbwfk9r]

Cap'n Ahab's favourite drop!