Old Wyeast smack pack/starter

[MikeyPipes86]

I'm planning on brewing tonight so I grabbed all my ingredients earlier this week from LHBS...and yesterday AM when I activated my Wyeast 2565 I noticed the date was 5/29/12...more than 7 months old! WTF!!

When I came home from work last night (10 hrs after smacking and shaking the hell out of it) there wasn't really any swelling which obviously raised a red flag. I made a starter with 1/2 cup of DME, aerated it well and pitched.

This morning there was what appeared to be the beginnings of a very loose yeast cake, but certainly no krausen or other activity.

What do you think...is 7 months really pushing the viability threshold (especially with no pack swelling)? Should I hold off brewing tonight or just monitor the starter throughout the day?

Thanks...

 

[hairy]

My LHBS always hold sales to clear their old smack packs (~ 10 months) and with a 1.5L starter, I never have problems these old yeasts.

There can be exceptions depending on how well the yeast is stored. Wait for yeast activity in the starter then decide. You wouldn't want to force the brew and end up with a slow or worse, non-fermentation.

 

[TheBiGZ]

Personally, I wouldn't use it. If there was no swelling after 10 hours, there are probably very few viable cells left...if any. You may be able to bring it back to life and bring the cell count back up, but the cells may have mutated and might produce some off flavor. Not worth it IMO.

 

[MikeyPipes86]

I'm torn...I've read a bunch of old threads; some say it should be OK others say to scrap it.

I do know for a fact it's been refrigerated this whole time at the LHBS; I watched him pull it.

Couple other things to note:

1. I don't have a stir plate;
2. I'm not making a big beer with it;
3. It would be pretty much 24 hrs exactly after making the starter that I would potentially pitch to my 5g batch.

 

[hairy]

Be it big or a normal beer, you will need good viable yeasts in good numbers. So, not brewing a big beer is no reason to pitch your current batch of yeast that hasn't shown signs of good viability.

Give the old yeast some time. Many good homebrewers make starters without stirplates and they turn out fine. So don't worry about the lack of one.

And if the case is that you don't see Krausen within the next 24 hours, your yeast is pretty much not good for use.

 

[WoodlandBrew]

It sounds like the yeast is alive, but it's slow going. It's likely that the viability is pretty good, probably around 75%, but the vitality is low. in storage glycogen reserves are depleted which are required to make sterols which aid cell permeability. With low permeability not much can get in or out of the cell making it slow going until the cell is built back up.

Because it was refrigerated mutation is not very likely. Sporification happens when the cells are active and without nutrients.

A microscope would help you make this decision.

However, if you want to play it safe, get new yeast, and save this one for another batch if it gets going.

Information on viability on yeast when refriderated:
http://woodlandbrew.blogspot.com/2012/12/refrigeration-effects-on-yeast-viability.html

And at ambient conditions:
http://woodlandbrew.blogspot.com/2012/12/yeast-health-when-kept-at-ambient.html

And some information on cell counts:
http://woodlandbrew.blogspot.com/2012/11/amscope-binocular-compound-microscope.html

 

[MikeyPipes86]

Here's a shot of the starter about 13 hours after being made. Some minor activity, no krausen.

Any further recommendation based off this status/timeframe?

Thx in advance.

 

[WoodlandBrew]

Just to get a sense of scale here is that a drinking glass we are looking at? If that's. The case then I don't think that will be ready in 11 more hours.

 

[MikeyPipes86]

No it's a large 32oz mug covered with foil. It was late last night and the best I could find. I boiled 2 cups of water with 1/2 cup of DME, chilled to 70f, aerated then pitched. Been swirling every hour or so today.

 

[WoodlandBrew]

Okay, that makes sense. It looks like about 1/2 cup of loose slurry at the bottom which is probably about what came out of the package. It looks like the very top has a low density of cells which is not encouraging. At this point they should be staying in suspension pretty well. If you do use this it will probably be a slow start, and might be a little under pitched.

 

[bufitfn]

I make starters all the time with old yeast, my LHBS sell outdated yeast for $3 each. I Start with a 2l starter on my stir plate, sometimes it takes a week to take off, after that I cold crash, decant and pitch into a 5l starter. in another week or so it is a huge yeast cake ready to go. I have yet to fail with this method. In the begining I was tossing the the starter after 3 or 4 days thinking it was dead, but after being patient, it always works...... Give youself enough time for it to start and you can save big bucks on yeast.

PS...wodlandbrew helped me to figure this out, hes the go to guy for yeast!

 

[MikeyPipes86]

I'm becoming pretty reluctant to pitch this if I brewed tonight. I appreciate the feedback...but I don't have a good gut feeling. This yeast is for the Spotted Cow clone which requires the cereal mash, so I'm not going to go through all the work if I'm going to be rolling the dice with barely viable yeast. Better safe than sorry I guess(?)

 

[MikeyPipes86]

Quick update on this...after a week in starter, the yeast finally started to wake up. I brewed on Thursday night and pitched...and 36 hours later have the most active fermentation I've ever had. Came home from work Friday to find a blow out. Had to install a blow off tube overnight and now I have it locked and bubbling away. Guess the moral is like everything else home brewing related: patience!