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?

[Ralph]

I am going to try putting them in the freezer for longer term storage. Something like this http://www.homebrewtalk.com/f13/guide-making-frozen-yeast-bank-35891/

 

I have only recently completed my stir plate and have yet to get a culture up and running as I have not had time... but I do intend to get onto it really soon. As soon as I have done a culture I will try putting the yeasties down in the freezer.

 

From what I have read and heard people are getting up to a couple of years from yeast vials in the freezer. I do kind of wish I had a deep chest freezer to put them in, as the standard upright ones are not great at maintaining a constant temperature.

[Ralph]

I would prefer a freezer next door than one out in Kaiapoi... when are you guys shifting?

[Chad Keven]

if you make a yeast starter at room temp, say 20C and the do the glycerine/freezer method does it mean that you could bang a couple vials on a courier before freezing? or do the vials need to be frozen quickly after being put in the vials?

just wondering incase any of you guys from the mainland would consider doing swaps through the post? just a thought

[Ralph]

Freeze/thaw will wreck yeast cells pretty quickly, but i can see no reason not to post a couple of fresh vials of through the post that could then be stored in fridge or freezer until culturing.

 

I might be keen for yeast swapping once I am up and running.

[Steve Popham]

I've done my starters in those jars that capers come in, any recommendations for where to buy proper vials?

 

I should look into the freezing slants and/or storing under sterile water but as I mentioned in another thread.... isn't it, in theory, possible to just culture from your last bottle of a brew (assuming you bottle condition that is)? I have cultured up from a barely visible amount of yeast in a commercial brew, got about a cup after 2 rounds of starter. Perhaps there are concerns over the lineage of the yeast that survives (too flocculant or not, etc)

 

What I have been doing, with success for the last year, is just washing and keeping, if the next brew is soon (1-3 weeks) I just pitch 1/2 of the yeast straight in and it starts right away. If it's older than 3 weeks I make a starter with a tablespoon or two of the slurry. 

 

 

[Chris Mills]

I've been using flasks from Laboratory Warehouse:
http://www.labwarehouse.co.nz

and vials from Alphatech:
http://www.alphatech.co.nz/

I suppose you will be fine, but I'm wanting to ensure vitality of yeast and also not wanting to put too many dead yeast cells into a new batch of beer.  The other concern is mutation of the yeast strain. It's my understanding that this is less of an issue with ale yeasts than lager yeasts, but what you might end up with is a flocculant yeast becoming powdery and less so or some other characteristic changes over time.

[Chris Mills]

Distilled, sterile water looks like a great way to store yeast long term. I will have to try this and see how hard it is to reculture from the stored yeast.

 

http://www.probrewer.com/resources/library/bp-healthyyeast.php

http://www.alsand.com/beer/yeast/index_E.html

http://hbd.org/brewery/library/SterileDW1096.html

[Chris Mills]

I've just cultured some slants and will deposit a small blob from these into sterile, distilled water and will try propagating from it once a month for a couple of years. I'll let you know what happens.

[Chris Mills]

I've just made up three distilled water storage (DWS) vials from the slants I mentioned earlier. Two will be kept refrigerated and the third will be left at room temperature. I've inoculated a fresh slant from the room temp DWS vial and will report back on what happens to it in a week or so. I'll make further slants once a month to track how viable the room temperature DWS is.

[Chris Mills]

A quick update:

I made a new slant from the room temperature DWS vial this weekend. Tons of viable cells still after 20 days at room temperature - in fact it looks no different from the first one I made.

[Liam Callaghan]

How long from slat to starter Chris?

 

I am only just starting on yeast cultivation and reading up non stop, quite an interesting side hobby, certainly feels like I am crafting my beer a lot more since I have started.  Will have a lab next to the workshop before the wife can blink...

 

I also started looking at it for yeast with my salami too, seems I can start it and keep it just the same which is awesome.

[Liam Callaghan]

Sorry was rushing this at lunchtime and realised this is the wrong thread to be asking this question on...