Frozen yeast bank frozen solid

[drunkinThailand]

So yesterday I started my first attempt at a frozen yeast bank. I was under the impression that by using the glycerin solution the vials never actually freeze solid, but this morning I woke up and that is what has happened.

I mixed up a solution 25% glycerin and 75% water, mixed 5 ml of that and 5 ml of yeast/beer in the vials, then put the vials in isopropyl alcohol and into the freezer.

What did I do wrong?

 

[Shawn0522]

I have been freezing yeast for a few years. I typically use slightly more glycerin but you should be fine. It does freeze pretty solid. I have had all but one batch work out great

 

[Shawn0522]

I am guessing you are perfectly fine. Make a starter and see how it turns out.

 

[drunkinThailand]

cool, i thought it was supposed to remain liquid. luckily i only used half of the yeast i made because i wanted to have a backup, and next time i will up the glycerin a little, but glad to know i'm probably fine.

how much glycerin do you use?

 

[Shawn0522]

cool, i thought it was supposed to remain liquid. luckily i only used half of the yeast i made because i wanted to have a backup, and next time i will up the glycerin a little, but glad to know i'm probably fine.

how much glycerin do you use?

Ill have to check but i believe it came out to 15 - 20%. I have my instructions at home.

 

[drunkinThailand]

thanks, i appreciate it

 

[Shawn0522]

thanks, i appreciate it

Ok so good news. I end up with the same consentration (12.5%) glycerin as you. I think you are 100% fine. You will probably see some seperation in your viles as well. I have always wondered if this is a problem, but yeast always takes off in a starter so havent worried about it to much. Best of luck to you! Since I have started doing this I have greatly reduced the yeast I buy. I keep 5 strains frozen and in 2016 I only bought liquid yeast once for a lager I did. I do still use some dry yeast as I sometimes decide to brew on a whim and no time for a starter.

 

[Sourz4life]

Yes, your fine. They are supposed to freeze. The glycerin just helps the cell walls from bursting when it freezes.

 

[b-boy]

Yes, your fine. They are supposed to freeze. The glycerin just helps the cell walls from bursting when it freezes.

Yes - water freezes and expands. Water + glycerin - not so much.

Here's an article on cryo-preparation. A little technical, and it applies more to animals, but I think the concepts are the same: http://www.fao.org/docrep/016/i3017e/i3017e04.pdf

 

[Sourz4life]

.

 

[lari]

i posted this a while back, frozen yeast slurry, no glycerin - made beer with it.
https://www.homebrewtalk.com/showthread.php?t=592477

 

[Sourz4life]

Sure, it can survive without glycerin(sometimes) but you drastically affect the viability and vitality of the strain. On a homebrew scale, not a huge deal but not ideal either.

 

[drunkinThailand]

great thanks everyone. i was wondering about the separation as well, so that is another good thing to know is normal.