Expired Yeast WLP001

[MSKBeerfan]

I had planned on brewing today but yesterday when I built my starter I noticed both of my yeasts were out of date. I had a one that was best by Nov. 2010 and one that was best by March 2011. Its been twenty-four hours and there not doing anything. Worse yet, the yeast looks brown on. The bottom I think my brew day is shot, any thoughts?

 

[MalFet]

There are likely living cells in there (at least the March 2011 one), but not in a quantity that you'll be able to get to pitching quantities with a single starter step. No chance of making it to the LHBS? This kind of thing is a good reason to keep a packet or two of US05 in the back of the fridge for emergencies.

 

[Revvy]

, 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.

To me that means it doesn't really matter the age of the yeast, because you'll be pitching FRESHER yeast, yeast you grew yourself.

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And my LHBS cells outdated tubes and packs of yeast dirt cheap 2-3 dollars each and I usually grab a couple tubes of belgian or other interesting yeast when I am there and shove it in my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.

 

[MalFet]

, 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.

To me that means it doesn't really matter the age of the yeast, because you'll be pitching FRESHER yeast, yeast you grew yourself.

If you are concerned only with yeast viability and not pitching rates, this is true.

 

[Revvy]

If you are concerned only with yeast viability and not pitching rates, this is true.

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You just keep building your starter to the size you need. THAT takes care of your pitching rate.

 

[phenry]

I built up a starter of Bell's propriety yeast from a 7 month old bottle of their amber ale (stuck waaay back in the fridge). If that had viable yeast in it, I'm sure your two vials had enough yeast to start growing something.

 

[MalFet]

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You just keep building your starter to the size you need. THAT takes care of your pitching rate.

Well, sure...but the OP's question was about whether or not the yeast would be usable today, right?

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[kappclark]

at the risk of hijacking the thread, is there anything wrong with stepping up a single vial of good stock (say a wpl001) to say 5 times the original volume (60 ml - 300ml), then using 100ml containers for your pitchable yeast (IOW twice the original size of the WPL001 vial) ..

Do this instead of harvesting/rinsing/storing yeast...create the yeast bank before any brewing..

 

[MalFet]

at the risk of hijacking the thread, is there anything wrong with stepping up a single vial of good stock (say a wpl001) to say 5 times the original volume (60 ml - 300ml), then using 100ml containers for your pitchable yeast (IOW twice the original size of the WPL001 vial) ..

Do this instead of harvesting/rinsing/storing yeast...create the yeast bank before any brewing..

If you pitch a tube of yeast into 300mL of wort, you'll increase the volume by five-fold but you won't get anywhere near five-times the yeast.

 

[Jud]

, 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.

Revvy you got all of the luck!!!

 

[kappclark]

If you pitch a tube of yeast into 300mL of wort, you'll increase the volume by five-fold but you won't get anywhere near five-times the yeast.

I didn't explain it properly == I am looking for a reliable way to increase the the 50 ML vial of yeast to say 200 or 300 ML...would one pr 2 starters accomplish this ?