Frozen yeast bank not freezing - Home Brew Forums
Register Now For Free!

Home Brew Forums > Home Brewing Beer > General Techniques > Frozen yeast bank not freezing

Thread Tools
Old 12-13-2008, 03:06 AM   #1
Apr 2008
Western Wisconsin
Posts: 124

I know this question has been asked before, but I could not find an answer. Is it ok for your frozen yeast bank to not freeze. I have put my yeast bank in my chest freezer at -5F. I used a 30% glycerin solution (I know it is more than is recommended) and my yeast won't freeze. Is this common/typical? Should I be looking to start over with a lower concentration of glycerin?


Reply With Quote
Old 12-13-2008, 11:31 AM   #2
Jun 2008
Poland, EU
Posts: 463
Liked 5 Times on 4 Posts

My samples never freeze - I mean, they are in liquid form, no ice crystals.

Reply With Quote
Old 12-13-2008, 11:57 AM   #3
Nightbiker's Avatar
Jul 2008
Dover, FL
Posts: 557
Liked 3 Times on 3 Posts

correct me if I'm wrong, but the whole point of using glycerin is to keep it from actually freezing (crystalizing) -ice crystals destroy cells.
Kegged: Big Bad Brown Ale (Brown Ale and Porter blend).

Plans: Oak-Smoked Porter, Honey Brown Ale.
Originally Posted by Jaybird View Post
we do it for the love of beer! Not for the love of money! We can all make great BEER! Not so much when it comes to money!

Reply With Quote
Old 12-14-2008, 03:21 AM   #4
Joe Camel
Mar 2008
Charlottetown, PE, Canada
Posts: 284
Liked 4 Times on 4 Posts

The purpose of the glycerin is to make sure that the ice that does form is of the small crystal variety. When large ice crystals form, they can cut and puncture the cell walls and destroy the cells.

15% glycerol(glycerin) is a good concentration to use. Too much can be toxic to the yeast when you're warming them up prior to pitching your starter.

If your samples aren't freezing in a chest freezer, it could be because of the high glycerol concentration or it could be that your samples are supercooled. take one and give it a good rap against the side of your freezer, see if that makes it freeze up.

Turn up the good, turn down the suck!

Reply With Quote
Old 12-16-2008, 12:34 AM   #5
Apr 2008
Western Wisconsin
Posts: 124

Well I appreciate the input. I did the rap on the side of the freezer. That is pretty cool. Mine turn to slush, but then turned back to a liquid within a few seconds. I guess I will try less glycerin next time.

Thanks everyone for the replies.

Reply With Quote
Old 12-16-2008, 03:29 PM   #6
Look under the recliner
pjj2ba's Avatar
Jul 2006
State College, Pennsylvania
Posts: 3,379
Liked 208 Times on 168 Posts

Freezing solid is fine - as long as you add the proper amount of glycerin. In the lab, our yeasts are stored in 15% glycerin at -80 C. The tubes are quite solid.
On Tap: Doppelbock O'fest, Pale Ale, cider
Kegged and Aging/Lagering: CAP, Ger. Pils, OKZ (std Amer. lager), CZ Pils, Amer. Wheat, Rye IPA, Saison
Primary: Ger Pils, CAP
Brewing soon: Pale lager, Amer. wheat
Recently kicked : (
Pilsner Urquell Master Homebrewer
(1st NYC 2011, 2nd NYC 2012)
P U crowns winners in its inaugural master HB competition

Reply With Quote
Old 03-17-2010, 03:20 PM   #7
Oct 2009
Posts: 64

I would be careful with tapping the vials to induce freezing. The point of freezing yeast is not to get solid ice crystals, but to lower the temperature. If the sample is at the low temperature of a freezer, then the biological processes are slowed which is why the yeast "survive" longer. Rapid freezing is what causes large ice crystals which damage the cell walls. Supercooling and then tapping the vials to induce crystallization is probably even worse then not using any glycerin at all. When laboratories are preserving living samples, they generally use refrigerators designed to slowly lower the temperature in order to prevent the large crystal growth I mentioned earlier (and what you see when you tap the supercooled vial).

If you are a fan of the effect you can see it on a bigger scale with a bottle of Corona in the freezer, just let it chill for a day or so then take it out and tap it on the counter. Its really cool to watch.
Primary #1: Nothing
Primary #2: Nodda
Secondary #1: Nothing again
Secondary #2: Even more nothing
Bulk Aging: League of Nations Imperial IPA (keg)
Bottle Aging: Banana wine, JAO Mead, Bohemian Pilsner
Drinking (bottles): Strom's Belgian Wit, Halfawiesen, Amarillo IPA
Drinking (keg): Corney Cream Ale

Reply With Quote
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Guide to Making a Frozen Yeast Bank FlyGuy General Techniques 829 02-02-2017 12:52 PM
Frozen yeast bank with yeast cakes? mrfocus Recipes/Ingredients 6 05-07-2015 05:18 AM
Yeast bank vials not freezing? c0bra Fermentation & Yeast 4 08-20-2009 08:18 PM
Yeast Starter from frozen yeast bank dfohio General Techniques 5 04-30-2009 07:32 PM
Frozen Yeast Bank- Strain Exchange? flyangler18 General Techniques 37 03-25-2009 01:17 PM

Forum Jump