I froze yeast, revived it and its fermenting !

*sigh... its been a hectic roller coaster weekend. I hope you guys aren't getting tired of my posts. I'll settle down after this one.

Here's the short version: I got frozen yeast to work !

Here's the long version.

My FIL unexpectedly brought me an activator pack of Wyeast 3942 from out of town. My LHBS was out of stock.
http://picasaweb.google.com/beermeister1/YeastStuff/photo#5046030916808457202

I purchased 7 small pill jars with rubber air tight seals from my local pharmacy for $35 cents each.
http://picasaweb.google.com/beermeister1/YeastStuff/photo#5046030912513489874 http://picasaweb.google.com/beermeister1/YeastStuff/photo#5046030912513489890

I gathered all my yeast equipment together. 2 syringes, one 5 ml and another 10 ml. The pill jars. A couple measuring cups, etc. I placed them in the pressure cooker at 15 PSI for 20 minutes.

Although they looked really good, those jars didn't work. The pressure cooker destroyed the inner rubber seal and thus they were no longer airtight. As a makeshift measure, I ultimately put plastic wrap over them and held it in place with rubber bands.

I kept the equipment in the pressure cooker with the lid on after it depressured until I needed it. I removed a small measuring cup, poured 50 ml of glycerin in it and heated it in the microwave until it was hot. Then I covered it with plastic and let it cool.

A few hours previous to this we had activated the yeast pack.

When the glycerin was cooled down, I got the syringes ready and got out my scale. I then swabbed the yeast pack and a pair of scissors with rubbing alcohol. I then cut the yeast pack entirely open.

One by one we took out the sterilized pill jars and put 6 grams of glycerin and 16 grams of yeast in and sealed them. We used one syringe for the glycerin and the other for the yeast.

I then put the yeast in the deep freeze. Our deep freeze does not have a defrost cycle and its about -15C in there.

The yeast was in the deep freeze for about 4 hours when I pulled one out, thawed it in hot water and made a starter from it. I pitched the starter into the chilled wort at about midnight. At 6PM the next day, 18 hours later, I have this.
http://picasaweb.google.com/beermeister1/YeastStuff/photo#5046030912513489858

One must remember that this was about 1/8th of an activator pack.

The yeast was fully frozen when I pulled it from the deep freeze. I didn't check if it was a solid or a slurry, I just thawed it and pitched it into the starter base. I know it was frozen because I turned the jars upside down and shook them and the yeast did not move. It was not a liquid.

There was no action in the starter base before I pitched it into the wort. I had also prepared another starter a few hours early from the yeast pack itself. Right now it shows a bit of activity, but nothing nearly like the yeast in the wort. My guess is that this yeast does not grow well in water and sugar. It seems to grow very well in wort. I think all starters for this sort of yeast are gong to need a wort base, not a water/sugar base.

This fermentation has an awesome aroma. This wort has orange zest and coriander in it and if it tastes half as good as it smells, it will be a great beer.

I have 4 more jars of this yeast frozen in the deep freeze. I think I've found an economical way to utilize liquid yeast for small batches.

I have to admit I just scanned this post. Sorry, there were lots of words! Anyway, it's good to hear someone actually got that to work. I figure your post will end up being a good resource whenever someone wants to try that.

That is pretty awesome. You can change $7 into less than $1 per batch. That is pretty good... I may try this. I have a kolsch fermenting now and am not sure I can do another with the weather rising daily. Maybe I'll do something similar to keep the yeast.

Please do try it and report back. I'd love to hear how this works for others.

Please also take pictures.

BTW, I got the glycerin at a pharmacy. $3 for 100ml. 500ml was $13. Just ask the pharmacist. The hardest part seems to be finding test tubes or a suitable container. Before I found the pill jars, I was going to get empty glass paint bottles from a shop that sells touch up paints for cars. When I found the pill bottles I didn't get those. I wonder how the lids for those jars would sterilize in the pressure cooker.

Maybe the pressure cooker is overkill ?

Yes it would be good to hear how the others do.

Cheers.

How about baby food jars? Seems like a good size and should hold up to boiling and freezing...

Oh, and you can buy some, have lunch and get busy...

I'm goint to give this a try to. Along with trying slants and plates to get an idea of the benefits of each method.

I'm also going to use empty white labs vials. they seem to be well suited for the job. But they cannot be autoclaved. I tries this and they turned white. So I'll keep them in star san for a while.

Since the number of cells in that will be in the seed stock is fairly lagre (compared to a slant or plate) I believe that very good sanitization should be goos enough. I'll see about this.

But the bottle of Glycerin U.S.P mentiones that it is not for ingestion at all. Is there a concern that a small amount of glycerin will end up in the beer?

Kai

step up the culture volume a few times which will dilute the glycerol to neglible levels (if your'e worried), should be ok unless of course you believe in homeopathy where the toxic affects will be magnified many many times fold

or you could just use the glycerin you buy for cooking!!

One very important thing having a frost free freezer will significantly (adversely) affect the viability of your cultures (over time) these freezer are constantly arseing about with the temp something the yeasties won't like.

Glycerin is used in wine making to increase the body of the wine. There are various grades of glycerin just as there are for other dual purpose products. I think the "not for personal consumption" warning is like a similar warning on shampoo.

As far as baby jars, we have an 8 month old in our house and have plenty of baby jars. All the ones I've found are much much bigger than the 25 ml that I need for the yeast.

I really like the pill jars and they would be perfect if they hadn't failed. I think I will try sterilizing them without using the pressure cooker next time.

I have to admit I just scanned this post. Sorry, there were lots of words!

Click to expand...

Here is the Reader's Digest version.

I sterilized everyting. I put 6ml of glycerin and 15 ml of activated yeast in containers and froze them. I revived the yeast by placing the container in hot water. I pitched the yeast. It fermented the wort. One can probably get ferment 8 batches of beer with one activator yeast package. One should be able to keep yeast frozen indefinitely using this technique.

One very important thing having a frost free freezer will significantly (adversely) affect the viability of your cultures (over time) these freezer are constantly arseing about with the temp something the yeasties won't like.

Click to expand...

You might be able to turn off the frost free functionality with a switch (or a wire cutters !) Conversely you could get the yeast frozen well and then put them in a small cooler filled with ice packs in the freezer. That way they wouldn't thaw during the defrosting cycle.

Ive been wondering about this too. Just curious, how did you come up with the ratio of 6ml of glycerin and 15 ml of activated yeast?

cpbergie said:

Ive been wondering about this too. Just curious, how did you come up with the ratio of 6ml of glycerin and 15 ml of activated yeast?

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Someone said the final mixture needed to be 25% glycerin. The extra ml was because we measured the glycerin with 2 strokes of a 3cc syringe.

There are a couple websites that discuss freezing washed yeast. They add a 33% glycerin/water mixture to it before freezing. I didn't want to add any water. The yeast from the activator packs is already a slurry. I just wanted to freeze that, so I picked 25% and went for it.

Here is what I used to freeze it in http://morebeer.com/product.html?product_id=19905

Will give it a try in a few month.

Thanks for sharing that. I think a local supplier has tubes like those. I'll check them out. I'm going to be freezing more yeast next weekend.

I am going to be try to Freeze some yeast here in the next few days and I was thinkin...I hope this is not to far off topic....but what if you frozze a White labs vial in a chunk of Ice. a contaner full of water and sumerg (spelling) the vial in it!

Would this counter act the frost free frezzer?

I believe the glycerin helps to keep the yeast cells from rupturing.

sorry I forgot to say that I will be useing glycerin aswell!

just doing some reading....
I've been successfully doing this for many years and have gotten as many as 15 10 gallon batches from one yeast purchase.
I started with a kit called the yeast Bank. It is still under $10, a bargain

http://www.countrywines.com/Winestore/beeryeast.htm

Couple questions:

1) Where do you buy glycerin?
B) How long was the starter going before you pitched it?
4) You said "Smaller Batches". What did you mean...?

BierMuncher said:

Couple questions:

1) Where do you buy glycerin?
B) How long was the starter going before you pitched it?
4) You said "Smaller Batches". What did you mean...?

Click to expand...

You can purchase at the pharmacy