How long for frozen yeast to wake up?

When I started brewing about a year ago, I decided to make a frozen yeast bank from my primary yeast cakes. I bought a bunch of glass testubes with screw on lids, and some glycerine. I would pour the yeast from the primary into a quart mason jar and let it settle in the fridge for about 30 min. After that period of time, the slurry would settle into 3 layers. There would be a thick layer of trub at the bottom, a beige yeasty layer in the middle and a fairly clear (beer) layer at the top. I would take a clean and sanitized syringe and suck up the middle layer and put that in the test tube to settle further. Once the test tube had settled, I poured off the beer floating on top of the yeast, and repeated the process of shaking up the quart jar, letting it settle, grabbing the middle layer and putting that in the tube. After 3 times, I would pour off about half of the beer in the test tube, and add an equal amount of glycerine. Shake and put in a cooler in the freezer.

sound good?

So about 7 months ago, I made a belgian using WLP500 after which I froze 6 tubes of yeast from primary. Earlier this week, I wanted to begin stepping up a tube to make a nice starter. I did not have DME, so I went to the store and grabbed 6 bottles of Malta Goya. I took a vial of yeast from the freezer (it was still liquefied in the freezer so the glycerine did its job) and let it warm to room temp. I took 1 bottle of Malta Goya, added 1 cup of water and boiled it for 5 min to get out the CO2, making a wort of around 1.044. I then put the wort in my flask and started it spinning while the wort cooled to around 80F. After that I pitched the vial of yeast (shaking of course).

after 48 hours, i still had no fermentation of the starter, so I dumped that batch and did the same procedure again. This morning, 12 hours later, no fermentation. I am using a stirplate.

I have about 650 ml of starter wort and a very small amount of yeast in the test tube. I estimate the yeast to starter ratio to be about equivalent to if you would add 1 new vial of white labs yeast to a 5 gal batch.

I do remember that when I did my Belgian 7 months ago, I didn't make a starter, I just added the vial to 5 gal. It took about 4 days to start fermenting, but the wort there was 1.077.

Do you think I need to wait longer for the frozen yeast to wake up, or is my entire bank dead?

Thanks all,
-J

Why do you just assume that it is the yeast bank and not using the malta goya? I've read on the forums that people have been pretty hit an miss with that.

Also what do you use as a sign of fermentation in your starters, a band of yeast in the bottom or seeing krauzen? I've never had any consistansy in terms of having krauzen on every starter, especially when using a stirplate, but all my starters have turned out. I've found that stopping the stirplate for a few hours allows a krauzen to form on a lot of mine.

Before you declare the yeast bank dead, try to change the other variables...go back to DME, or stop the stirplate after a few hours, or use O2 and don't turn the stirplate on, things like that.

Revvy said:

Why do you just assume that it is the yeast bank and not using the malta goya? I've read on the forums that people have been pretty hit an miss with that.

Also what do you use as a sign of fermentation in your starters, a band of yeast in the bottom or seeing krauzen? I've never had any consistansy in terms of having krauzen on every starter, especially when using a stirplate, but all my starters have turned out. I've found that stopping the stirplate for a few hours allows a krauzen to form on a lot of mine.

Before you declare the yeast bank dead, try to change the other variables...go back to DME, or stop the stirplate after a few hours, or use O2 and don't turn the stirplate on, things like that.

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Yep I could try and change some other things for sure. To tell if i've fermented, I take refracto readings. I started at 11 brix and still am at 11.

Thanks for your suggestions,
-J

I would start with a very small starter (100-200ml) and I would use wort at around 1.020 but YMMV. Need to wake up those puppies before stepping up! IMO you are overwhelming those bad boys. Also it may take 2-3 days to get them going.

Poobah58 said:

I would start with a very small starter (100-200ml) and I would use wort at around 1.020 but YMMV. Need to wake up those puppies before stepping up! IMO you are overwhelming those bad boys. Also it may take 2-3 days to get them going.

Click to expand...

+1 I started my yeast bank a few months ago. I did a trial run to test the process by making a starter from a 4 year old pack of dried yeast. I was amazed that the old yeast were still viable. I froze 4 samples. I didn't do the fill vial let settle decant refill process so I only wound up with about 3ml of yeast in each sample. After 2 weeks I defrosted 1 sample and made a 150ml starter and pitched the sample. It took 3 days for it to wake up and 1 day to ferment out. I stepped it up to 500ml and 24 hours later I had a good 1/4" layer of yeast in the 500ml flask.

Give it more time.

I plan to revive the other samples at 6 month intervals to see how long they can last frozen.

I've read that you should let your vial of frozen yeast sit in your fridge for a day to let them thaw out before you warm them up further by bringing them out into room temperature.

so they took off at 3.5 days. i'm now ready to start my second ramp-up. I expect this one to go much faster.
-J

To summarize some advice already mentioned in the thread, it is really essential that you step up your starters when using frozen yeast. Never exceed 10 times the volume from one starter to the next (including your vial volume!). I typically go from about a 100 ml starter, to 750 ml to 2 liters. If you jump into a larger volume right off the bat, you will have a big lag time (which is prime time for an infection) and your yeast won't be as healthy as if you stepped up the starter. Also be sure to add yeast nutrients and aerate/oxygenate every starter (particularly the first one!).

For yeast nutrients, I really like using dried yeast (brewers or bread). Just boil a good pinch of it with your starter wort. Some of the commercial yeast nutrients are actually toxic at high concentrations, and was always worried that I might measure a small amount incorrectly and hurt my first starter. There is less worry with boiled dry yeast.

thanks flyguy. I was wondering what to use for inexpensive yeast nutrient. That's a great idea. I did a bit of research, and some of the guys that distill are using anything from tomato juice to Geritol vitamins for their nutrient.

-J

FlyGuy said:

I typically go from about a 100 ml starter, to 750 ml to 2 liters.

For yeast nutrients, I really like using dried yeast (brewers or bread). Just boil a good pinch of it with your starter wort.

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I use pretty much the same technique. I might add I use rather thin wort 4-5 Plato, I boil it with some bread yeast and 1-2 pellets of hops.
I use 100ml starter, I let it run for 2-3 days, then I step-up to 500 ml, after 1 day to 1000 ml, and then sometimes to 2-3L if necessary. It usually takes 6-7 days to have the starter ready.