Let's Freeze Some Yeast

[[email protected]]

Bribie,

Good to see you having a go. It takes me months to get my crap together to do these things!

Just following through on Unrealeous. I would autoclave/pressure cook the tubes with the glycerin in them with the lids on and only take the lid off briefly to add yeast etc.

How are storing in your freezer as this is also critical to the process? Are using ice packs and a small esky to avoid the defrost cycle. I have purchased a few of the technice packs (50c each) to pack the vials in.

Maybe add a few photos of how you are storing to complete the OP.

 

[drsmurto]

Did you sterilise the glycerine?

 

[Bribie G]

I microwaved the glycerine / preboiled water mix in one of the pyrex cups as per the American Website and syringed immediately into the tubes then covered them.

 

[drsmurto]

I microwaved the glycerine / preboiled water mix in one of the pyrex cups as per the American Website and syringed immediately into the tubes then covered them.

All good, just didn't notice it in the steamer. :icon_cheers:

Like you i want to do this without having to buy a pressure cooker.

 

[drsmurto]

Huge thanks bribie, just followed the link to another link on canning wort - Link

As it happens my HLT is actually a Fowlers Vacola preserving urn and i own several boxes of preserving jars as well as 100s of jam jars.

I have an excess of JW trad so making up 20L of wort at 1.040 and then preserving them for starters later sound much simpler than forking out money for extract.

I had done this in the past and frozen the wort in 1.5L juice/soft drink bottles but that takes up a lot of space in the freezer. Preserving them means they don't need to be frozen.

Cheers
DrSmurto

p.s any comments on not boiling the wort prior to putting it in the preserving jars? This would be the same as doing a boil with the lid on.

 

[choppadoo]

I work in a molecular biology lab, and we regularly make glycerol stocks for long term storage. Usually for bacterial cultures, but the principle is the same for yeast. I have just started making glycerol stocks of wyeasts that I buy. We store in -80C freezers, basically the colder you get it, the longer the cells keep their vitality, and the less often you have to re-culture. I make my glycerols with a final concentration of 25% glycerol, the other 75% being taken directly from yeast smackpacks. I make 1mL tubes, if you have good sterile procedures, you can make starter cultures from a single glycerol stock almost indefinitely (this will also reduce the amount of freezer space required). This you do by streaking a swab from the glycerol onto an agar plate, selecting a healthy colony and innoculating into progressively larger cultures (e.g. 3mL, 25mL, 250 mL, 1L, wort!). The agar plate step is probably not neccessary in a homebrew situation. This protocol will only work if you have good sterile technique; bacterial cultures are prepared in exactly the same way! Also, do not chill the glycerols slowly, reccomended best practice is to snap-freeze in liquid nitrogen before placing into the freezer, although this is not really neccesary.
If done correctly, glycerol stocks are a much better long term storage option for yeast than slants; they will retain vitality for much longer.

Cheers,
Brad

 

[Nevalicious]

I microwaved the glycerine / preboiled water mix in one of the pyrex cups as per the American Website and syringed immediately into the tubes then covered them.

Whoops, I used just 25% glycerine, and the rest was plain ol smacked Wyeast. Forgot the water...

I'm sure it will be fine though. Maybe <_<

 

[argon]

Froze me some yeast last night :beerbang:

Tried it first with some good ol' US 05... i figure if things don't work out no loss. If it's all good i'll be freezing some precious 1469 i have in the fridge.

Couldn't have been easier... especially considering i used sample jars and syringes that are pre-sterilised in the packet.
Just made up my solution of Glycerin and pre-boiled water, brought it to boil again in microwave, added to sample jars, added appropriate amount (35ml in my case), then took some top cropped washed yeast and syringed 10ml each into 5 jars.

I now have 50ml of washed, frozen top crop US05 ready for starting up whenever i want. I can see this yeast harvesting and storage thing getting out of hand and filling up my freezer with sample jars of murky brown liquid. :blink:
:icon_cheers:

 

[davo4772]

I'm not too fussed about using yeast over and over but i would like to reuse yeast at a later time one or twice to reduce costs.

I am able to access larger sterile containers. I wonder if you could freeze the required amount (for another batch) of yeast cake in one container.

Prior to brew day unthaw the yeast cake, add a pint or so of starter to rouse the yeast and Bob's your aunty.

Can't see why it would not work. Depends on loss of viability during storage. The minimum number of cells you put to sleep might not wake up.

My attraction to this method would be not having to step up more than once.

Cheers

 

[Bribie G]

OK it's been nearly 4 months and the original tubes from the OP have been sitting in the back of the freezer - I've just cubed a London style Special Bitter and decided to thaw a couple of tubes and see how they go.

I collected a litre of end-of-runnings out of the urn into a Schott Bottle and let them settle out, and got about 300ml of clear stuff that I've poured into another 1L Schott bottle, and slid a couple of frozen plugs out of the test tubes, good shake, and it's now probably around 12 degrees, let it warm up and see how the cow sits in the ol' cabbage patch by tomorrow. :icon_cheers:

 

[Punkal]

Good luck Bribie... I hope they are trying to climb their way out the top of the schott bottle by tomorrow morning...

 

[Yob]

let it warm up and see how the cow sits in the ol' cabbage patch by tomorrow. :icon_cheers:

Hay Bribie.. just curious, Dave Line in "The Big Book of Brewing" talks about freezing a "Ball" gained by collecting Yeast from the Krausen (the middle section).. did you give that a go at any point?

I dont know when it was written but is this method no longer used?

Great pictorial too.. nice one

:icon_cheers:

 

[Bribie G]

Comrades
It is with deepest sorrow that I report that the brave and patriotic yeasties did not make it through Cryo.



I suspect my freezer just wasn't cold enough, well onto some slanting now and see if that works better - have the agar.

In recognition of their selfless sacrifice a Plaza has been renamed in their honour "La Plaza de Los Valientes Levaduras de La 18 Abril" and the Chairman will snip the ribbon this afternoon. :beerbang:

 

[adryargument]

Not good, i may need to test mine....

 

[QldKev]

Comrades
It is with deepest sorrow that I report that the brave and patriotic yeasties did not make it through Cryo.

View attachment 45323

I suspect my freezer just wasn't cold enough, well onto some slanting now and see if that works better - have the agar.

In recognition of their selfless sacrifice a Plaza has been renamed in their honour "La Plaza de Los Valientes Levaduras de La 18 Abril" and the Chairman will snip the ribbon this afternoon. :beerbang:

I wonder what the issue is with the yeast? I have yeast in test tubes dating back to June 2009, that has only been stored in the fridge. They are still happy yeasties again within 24-36 hours (CPA is sometimes up to 48hrs) getting back to doing their rude stuff in my wort. I would have though a freezer even at the higher end of the freezing range would have been plently cold, when my fridge is set to 6.0c.

QldKev

 

[Bribie G]

Yes it's a mystery. I've had to move on quickly with the current brew so I'm using some 1469 cake instead. I think I'll do up a LDME wort, pitch another couple of tubes and see if they do kick off after a few days. However no movement at all over the last couple of days, and I'd expect something.

 

[ratchie]

Are you letting the yeast thaw out for a couple of days before pitching.

 

[MHB]

I think you didnt have enough Glycerine, from my understanding you need enough to act as an anti freeze.

When I was mucking around with this a couple of years ago I put the yeast slurry into tubes, let it settle overnight, removed the superannuant liquid (beer) then topped up with 30% Glycerine solution, target being 25% Glycerine and there is some argument that up to 35% might be better.

Your Glycerine content is less than 15%.

Be worth trying again, I got good viability up to 2 years out.
MHB

 

[QldKev]

What MHB said makes sense. If it froze you would have ruptured the cell walls; with a higher level of the ani-freeze it would prevent that. Got me thinking about saving off some yeast, and giving it a go.


QldKev

 

[Nevalicious]

Its definitely worked several times for me now...

I will go with the suggestion Bribie that you didn't have enough glycerine. I really dont measure it out as such, but rather, roughly fill the vial (20ml) 1/3rd full of glycerine, then top up with yeast slurry/smackpack etc. I've had no issues thus far getting one going again.

As per your post a few days ago, I generally do the first step up on about 300ml of wort, no more...

Anywho, just my 2.43 cents

Nev