Reviving Old Yeast

[Tobor_8thMan]

With everything going on in 2020 I didn’t get to my pack of Wyeast 2112 as originally planned. The pack is dated 1/27/20. At the current date/time, BeerSmith indicates the yeast only has 7% viability.

BeerSmith recommends a 2-stage starter. I smacked the pack on Tuesday, December 15, 2020. By Thursday the pack was firm, but not swollen as smack packs in the past. I realize there are a lot of jokes just waiting with the words “smacked” and “swollen”, but please realize I’m writing about Wyeast.

On Thursday I made a 1.036 1st stage starter solution as recommended by BeerSmith of 0.32L and 1.082 DME. I cooled the small wort and pitched the Wyeast 2112 at 5PM EST. Been on a stir plate since then with the stir plate gently moving the wort (in other words, nothing crazy).

Checking several times on Friday, December 18, 2020, I see no apparent activity.

Is the yeast dead?

Should I allow the 1st stage to go longer on the stir plate.

I appreciate constructive input on this matter.

 

[day_trippr]

Let it ride. There've been lots of "back from the dead" posts that always seem to have the yeast resurrected in the end...

Cheers!

 

[Tobor_8thMan]

I've read the posts too and that's why I even attempted to revive the yeast. When should I see activity in the 1st stage?

I'd like to brew on Monday using the yeast. Planned on stepping it up on Saturday, but without noticeable activity now, I'm not sure about Saturday's plans.

 

[KeizerBrewr]

When you turn off the stir plate and walk away and come back a half hour later do you see any bubbles in the solution? If you do, the yeast is still going. It has only been roughly 24 hours since you pitched it into your 1.036 wort. I would let it ride. It will most definitely not be ready for a brew day until next weekend. If i were you, I would let it go until tomorrow morning, pour off some liquid and take a gravity reading. Right now, that's the only way to know if you have any activity. The yeast could be so weak that it could take a couple days to make any headway.

 

[Tobor_8thMan]

I will turn off the stir plate and check. Thanks for the input.

 

[day_trippr]

iirc the last similar "are they alive?" thread ran almost a week before things started happening...

Cheers!

 

[KeizerBrewr]

There have been times, I have had no clue if I had any activity in my flask, so I just turn off the plate and walk away, come back half hour to an hour later and inspect/look for any action. If there are bubbles or any action inside, turn the plate back on and let it go. I usually turn my stir plate up to where it just starts to produce some bubbles in the hopes to have good oxygen exchange in the solution.

 

[BeerFst]

I have revived yeast this old several times. I like to do a 500ml at halfish strength 1.025 ish then a 1L at full 1.040, followed by a 2L at 1.040.
I would say without fail the first 500 shows almost no activity but at the 1L stage it takes right off

I’d try stepping it up

 

[Tobor_8thMan]

I have revived yeast this old several times. I like to do a 500ml at halfish strength 1.025 ish then a 1L at full 1.040, followed by a 2L at 1.040.
I would say without fail the first 500 shows almost no activity but at the 1L stage it takes right off

I’d try stepping it up

Thanks. Yes, BeerSmith recommends a 2 stage. First stage is small and then the 2nd stage is 4.34L.

As soon as I head back down to my brewery I'm turning off the stir plate for a while to see if there is any activity.

 

[Tobor_8thMan]

Turned off the stir plate on Friday evening. Checked on Saturday. Nothing. Over my shoulder I heard "Bones" McCoy say "It's dead Jim!"

Headed out to a local hbs and purchased a fresh pack of White Labs WLP810 with a use by date of May 12, 2021 so I know it's fresh. Added the WLP810 to the starter and turned the stir plate back on.

 

[Vernacular]

You think you have old yeast? I just found two packs of CRY HAVOC in the fridge! This yeast isn't even called by that name any more... wish me luck with it... Stay tuned.

 

[KeizerBrewr]

You think you have old yeast? I just found two packs of CRY HAVOC in the fridge! This yeast isn't even called by that name any more... wish me luck with it... Stay tuned.

I want to hear how it goes as well!

 

[Tobor_8thMan]

Either the Wyeast 2112 wasn't as dead as I thought or the WLP810 was vibrant or the stepped-up starter was potent as I achieved fermentation within 3 hours of pitching the yeast.