Long Term Yeast Storage.

[Chris Mills]

I've been looking at ways to store yeast long term and am finding plating (or slants) to be an easy process (even if it does need doing every three months).

I've been reading about using distilled water as a long-term storage medium (at room temperature), and if money were no object and I had all the room in my brewery that I could want (I don't) I'd look at at cryogenic storage in aliquots stored in liquid nitrogen.

I'd like to have this a thread for discussing yeast management. Anyone want to join in?

[Chris Mills]

Hi Liam,

It's roughly 8 days from a slant with 50ml of starter wort to 350ml of good, thick slurry in 2L of starter wort. I scale it from 50ml to 250ml to 500ml 2L. Sometimes I can stretch it for a couple of extra days, but it's never any quicker than that.

[Liam Callaghan]

Thats not bad at all.  I thought it was going to be 12-14 days.  Thanks for that Chris, I added you on my friends list I hope you don't mind, I might question the bejesus out of you when I get started, depends if it all runs smoothly or not I guess :) 

Looks like I'll be looking at a yeast farm then.  Be very interested in how you get on with your long term storage and any yeast swap shops.  Happy to buy something that people dont have yet etc.

[Ralph]

I have got my stir plate up and running and have made a couple of cultures. I now have in my freezer in a glycerine mixture a Wyeast British Ale II and will be adding a Wyeast Dennys 50 in a couple of days. 

As I have not yet grown a culture from the stored vials I have no idea how successful my freezing method has been. I will probably get around to culturing one of the vials of British Ale over the Christmas break...

[Dougal]

You should be pleasantly surprised. I kicked off a frozen vial of 1272 the other day and it was very quick to start up despite being over a year old.

One thing I read about that method is that it's a good idea to ease the temperature transition to freezing by refrigerating for 12 hours first. Often you'll get some separation between yeast and glycerine over that time, so agitate again before it goes into the deep freeze.

[Ralph]

So if my yeast was in the starter bottle in the fridge for a couple of days before I put it into glycerine it would be likely to have had some of the same effect? I guess adding it to room temperature glycerine would not be helpful tho?

Keen to get some swaps going at some stage.

[Dougal]

Hard to say, all I remember reading was that yeast that was refrigerated before freezing had much better viability.

Sure, happy to. I'd love to get some of that Denny's 50.

Did you ever find a big pipette to transfer the yeast to the vials with? 

[Ralph]

Yup, found a couple of 10 ml pippettes that do the job.

Would you like some Dennys in a vial + glycerine, or would you be keen on some fresh slurry? Probably ready tomorrow (Friday).

[Dougal]

Ta, but I've got lots on the go at the moment, so maybe a vial sometime. Let's do swaps over a post xmas pint.

[Chris Mills]

I've just made two new slants from the room temperature DWS vial and am happy to report that after two months there are still heaps of viable yeast cells in there. So far this appears to be working just fine and shows that I may be able to maintain my core yeast library without refrigeration.

[Ralph]

Wow, that is great. It will be interesting to see how they go long term Chris. Have you got a still or something to get your DWS?

[Chris Mills]

I dished out $15 to buy 3L of distilled water from the local pharmacy. It's highway robbery, but was the only way I could manage it.

[Liam Callaghan]

A simple pot still would be ok to make this wouldn't it?