Expired Yeast?

Bought a smack pack of Wyeast North American Lager when it was around to have on hand. Only now getting around to using it (maybe). Purchased it in August 2011, but it's probably from April-June 2011, since that's when it was available as part of the Private Collection. 2L Starter shows no signs of fermentation... no visible yeast, no CO2, no smell (other than sweet wort). Should I bag it and just get a couple packs of W-34/70? Mr Malty says that the viability of something produced on those dates is only 10%.

If you make a starter, then the age of a yeast isn't really an issue. When you make a starter, and grow it, you're replicating more yeast to make up for any loss. You're making new, fresh yeast.

Bobby M did a test on year old stored yeast here; https://www.homebrewtalk.com/f13/testing-limits-yeast-viability-126707/

And my LHBS cells outdated tubes and packs of yeast dirt cheap 2-3 dollars each and I usually grab a couple tubes of belgian or other interesting yeast when I am there and shove it in my fridge. and I have never had a problem with one of those tubes.

I usually make a starter but I once pitched a year old tube of Belgian High Gravity yeast directly into a 2.5 gallon batch of a Belgian Dark Strong, and after about 4 days it took off beautifully.
The purpose of a starter is to reproduce any viable cells in a batch of yeast....that;s how we can grow a starter form the dregs in a bottle of beer incrementally...and that beer may be months old.

Even if you have a few still living cells, you can grow them....That's how we can harvest a huge starter (incrementally) from the dregs in a bottle of some commercial beers. You take those few living cells and grow them into more.

If you don't have a stir plate, you may have a hard time growing whatever yeast is alive, or may make for a troublesome starter....If you don't have a stir plate, make sure your swirling your starter every so often....I was given an outdated ringwood strain from my LHBS and it was very troublesome,,,not worth my time...depends on how much time you have on hand, dry malt extract and most of all curiosity to successfully grow your yeast strain up...
My experience is based on one outdated wyeast strain, other strains may be hardier in their dormancy period and may be more apt to be successfully grown up.
Good luck!

Thanks guys. I do have a stir plate and I have propagated a healthy batch of yeast from bottle dregs, but I'm concerned about having enough in time. Started my starter on the stir plate on Tuesday. Brewing this Saturday.

I didn't check the OG, but I imagine at a 10:1 ratio of waterME, I should probably be in the neighborhood of 1.040. I'll check the gravity tonight and tomorrow (hate to have to put the sample back after using a turkey baster and the hydrometer tube instead of a wine thief) and see if it's much lower.

I guess I'll pick up a couple packs of W-34/70 just in case. Maybe I'll just pitch one pack of dry with the full starter. I am doing 8 gallons of lager (5+3) and planned to do 5 with the Wyeast North American Lager and 3 with W-34/70. Wanted to have two different but similar lagers. Maybe I'll add something to the secondary of the 3 gallons to mix it up (lime peel for a hint of lime lager?).

Thanks again for your input.

This is one of those instances where I'd let the wyeast pack swell up to verify that the yeast is indeed alive. Once it has swelled some, I'd make a starter on the stir-plate. It gives me reassurance that I'm not wasting my time on a dud!

M_C

Misplaced_Canuck said:

This is one of those instances where I'd let the wyeast pack swell up to verify that the yeast is indeed alive. Once it has swelled some, I'd make a starter on the stir-plate. It gives me reassurance that I'm not wasting my time on a dud!

M_C

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Thanks, but I already made the starter. Didn't want to wait for the smack pack to swell. Maybe I should have in order to confirm viability, but that would have been a day wasted when yeast could be multiplying.

imtrashed said:

Thanks, but I already made the starter. Didn't want to wait for the smack pack to swell. Maybe I should have in order to confirm viability, but that would have been a day wasted when yeast could be multiplying.

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Your starter is confirming viabilty and reproducing the yeast.

It even says on the wyeast website that smacking the pack isn't necessary. It really is a gimmick. If you're making a starter (whether it's a new pack or not) you really don't need to wait for the stupid pack to inflate. Just slit it and add it to the starter.

You're right that it's a day wasted waiting for it to inflate, and that is regardless of the age of the yeast.

In the future, if you have an old smack pack, make a smaller starter and step it up once you see some signs of life. Start with something like a pint. The yeast will be able to colonize it faster and there will be less chance of contamination taking over. Starting with 2L (a little over a half gallon) with old weak yeast will take a while to catch up. If you have pure O2, give it a shot every day or two until it takes off. I've found that this helps bring the cell count up quicker, even with a stir plate.

BBL_Brewer said:

In the future, if you have an old smack pack, make a smaller starter and step it up once you see some signs of life. Start with something like a pint. The yeast will be able to colonize it faster and there will be less chance of contamination taking over. Starting with 2L (a little over a half gallon) with old weak yeast will take a while to catch up. If you have pure O2, give it a shot every day or two until it takes off. I've found that this helps bring the cell count up quicker, even with a stir plate.

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Good info!

Speaking of....That's another thing folks can do when they find outdated yeast. (In fact one of the vendors on here sells their expired yeast at a deep discount.)

Make up a starter, build it up, wash it and jar or freeze it. In other words if you get yeast that is expiring and can't brew, harvest it and save it for later.

Revvy said:

Your starter is confirming viabilty and reproducing the yeast.

It even says on the wyeast website that smacking the pack isn't necessary. It really is a gimmick. If you're making a starter (whether it's a new pack or not) you really don't need to wait for the stupid pack to inflate. Just slit it and add it to the starter.

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Half the time I can't tell that there's activity in my erlenmeyer (when it's turning), that's why I wait on the Wyeast pack to inflate before going through the trouble of making a starter.

Of course if one's time is limited, that's a different story. But if I use an older yeast, I'm not gonna make a starter 24 hours before brewing. But... That's just me.

M_C

It's confirmed. Gravity tonight is only 1.034. I'm guessing my guesstimate measurements in water and/or DME were probably slightly off and this is my original gravity. I doubt there's any yeast activity going on. Going to play it safe and pitch dry yeast. Thanks for your input.

When i grow a yeast sample in my erlenmeyer flask i rip a clean sandwich bag off of a roll of hundreds put it over the top of the flask leaving the maximum amount of bag above the lip of the flask and hold it in place with a multi wrapped tight elastic band. Scientific side of me is confirming the viability of the yeast before pitching(with much beard stroking and saying Hmmmn to myself) into the main event. The wee boy side of me is jumping up and down waiting to see the magical invisibly inflating bag. Please try it out for yourself but be honest about what side of you is enjoying it the most!

OP, don't bin it yet. Give it some heat and leave it a week. You might get a decent colony for your next lager.

Three days later my yeast starter has taken off. It's cloudy now and smells like fermentation. I'm a happy camper.

imtrashed said:

Three days later my yeast starter has taken off. It's cloudy now and smells like fermentation. I'm a happy camper.

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That's good news. I guessed it would eventually start up.

It's my first go with lager yeast. Didn't realize there'd be such a lag. Or maybe it just took that long with the little bit of viable yeast in there to multiply to this extent. Thanks.