Here is a pic of a 3rd generation safale s-04 dry yeast I bought back in march... This was sitting in my fridge with trub for about 60 days and was recovered from a batch that I pitched right on the cake.
I just racked a Czech Pilsner to secondary this week made from a wyeast smack pack with a date of Mar 2008. took a few steps on the stirplate (using sterile wort) but I had activity in 24hrs @ 50 degrees.
I know many people are subscribed to this thread, so I thought I would post my experience. I made a 1L starter yesterday from two jars of washed Brewferm Lager yeast. The sticker I had on the jars was dated 1-11-11. That makes this yeast almost exactly 15 months old. I got up this morning before daylight and it showed no signs of life, and the yeast and settled back to the bottom and my stir plate had threw the magnet. I gave it a shake, put it back stirring and went turkey hunting. I just got home, found a small layer of foam on top. I threw on an airlock for a moment just to see if it was off gassing, and SURPRISE! I'm getting bubbles every 15 seconds. I thought this one was a goner. I'm going to let it do its thing then step it up. Thats proof that these little guys are tougher than we think!
There's a good BrewStrong episode about yeast management (3/8/2010). One thing that was emphasized is that just because the yeast is alive and makes beer doesn't mean it is healthy and will have the flavor profile you would expect of that particular yeast strain.
Then again, if it makes beer that you're happy with, it's certainly a real easy method and very RDWHAHB. I'll be trying this at some point, but eventually a frozen yeast bank is in the cards considering how hard liquid yeast is to get out here
Good thread, even if it's been the walking dead for 2+ years Here's some follow-on material....
I suspect results in this area may differ from strain to strain, so I was encouraged to read a previous post on this thread about Wyeast Belgian Schelde 3655. I'm brewing the BCS Belgian Pale Ale this weekend, which calls for this yeast. When I went to the LHBS, they had exactly one very outdated smack pack of this. They have a fridge dedicated to yeast, so I felt it had probably been well-handled, so I went for it.
So here follows a few posts to chronicle the success or failure of resurrecting this yeast.
@SmallBatchBrew Wyeast calls this the flocculation on this "moderate", so I don't know if this qualifies for your interest.
My recipe is a 1.052 OG, so I don't need a monster starter. I'm brewing 5g so normally, I would just make a 1.8L starter and call it good. I'm going to add one step on this just to ease it back into the world.
The package is dated September 29th, 2014, so it's now about six months old. I warmed it while I was at work today, and smacked the pack at 6:00pm. My plan is to let the pack swell, pitch into an 800ml 1.020 starter, and put it on a spin plate for 24 hours. If that goes well, I'll step that up to 2L.
Here's a shot of the pack about an hour after smacking. No real swelling, but that's normal for smack packs in my experience. I'll post another shot in about two hours when I would normally expect to see significant swelling.
Okay, so I checked on the smack pack at 9pm last night and no swelling. So I filled two six-packs of bottles with two different beers currently on-tap and went off to play poker with the boys.
When I got back at 1am, the packet looked good and fat - photos below. So I cooked up a 1L starter with 50g of DME and 1/8 tsp of yeast nutrient, shooting for 1.020. Chilled and filled a 2L flask. The wort tested out at 1.017, Close enough for government work. I usually boil with 100-200ml extra water to account for boil-off.
Day 2 in this process - 12 hours after putting this on the stir plate, 2pm check-in.
Good tan yeast color in the flask. Good clean yeast odor with faint phenolics. No signs of krausen, but that's not unusual for step 1 starters in my experience. Plan to let this spin for another 12-18 hours, then cold crash, decant the clear beer, and make a second stage 2L starter.
I'll re-use yeast that's up to 2 months old, but I don't bother making a starter. I just decant the liquid from the top, swirl up the yeast and dump it in (after doing a sniff test as mentioned by someone else earlier in this thread).
Day 4 - 10am. 2nd Step starter has been spinning for 24 hours. Yesterday was a brewday. I pitched the Step 1 starter to the Step 2 wort at about 10am. By 4pm, I noticed that there was a nice little krasuen.
Here's a shot of it this morning sporting a very healthy tan color.
Coincidentally, it's sitting in a fermentation chamber with a beer that is ready for cold-crashing, so I just removed the stir-plate and crashed the chamber. Should be ready to pitch tomorrow. The wort is sitting patiently in another fermentation chamber at the proper pitching temp - 65F.
For the curious, here's how I'm calculating the starter...
First of all, I'll start with 5.5 gallons of 1.052 wort. The calculator estimates I need 201Bn cells.
Most sources say a 6 month old smack pack is 0% viable. But we know better but I'm not overly optimistic, so I started with the assumption of 10% viability. I use BrewersFriend.com for multi-stage starters and it's always worked well. For this, I just input different yeast-mfg-dates until the calculator said 10% and went from there.
After a 1L, 1.017 starter on a spin plate the estimate was that I had 78Bn cells.
After pitching that starter to a 2L, 1.036 starter, it estimated I had 365Bn cells.
So that's a healthy percentage (something like 75%) over the recommended pitching rate. I figure these are all ball-park estimates, and that even at that, I'm not risking over pitching by a enough of a margin to worry about.
I revived a vial of WLP029 that was 4 months past its use by date this past weekend. Pitched it into 1.020 wort and it perked up within a day. I let it finish, and since I plan to use it next month, I poured the good stuff into a Mason jar and tossed it in the fridge. I'll do a starter with 1.040 wort prior to brew day and let it rip.
Update: after pitching the decanted yeast from the second stage starter into 5g of well-aerated wort, I had a strong fast-start (6 hours) fermentation with about 1/4 qt of blowoff through a big blowoff tube - and that was after 10 drops of fermcap. I maintained temp at 65F.
So far so good - at least it's making all the right signs for a healthy fermentation!