Let's Freeze Some Yeast

[Yob]

Just threw in a Greenbelt last night that had a %50 mix... It's now making a horrible mess all over the kitchen table..

Ok I guess

 

[idzy]

Delightful

 

[Yob]

I pitched 20ml into a 2lt starter, it's going bananas after 24hrs...

Destined for my mandarina Bavaria cube

 

[idzy]

So I have done a mix of 20ml glycerine and 25-30ml yeast into 10 tubes.

Put them in the fridge last night. Gave them a shake this morning and placed them in an open container with ice laid over the top.

Will keep all posted on success.

The yeast is Wyeast 3787 - Trappist High Gravity Yeast

 

[Yob]

an open container? I put mine in a sealed container with an ice brick

If you want some 001, 002, 090, 099, 1318, 1217, 1728, Greenbelt, er... and some other ones... lemme know

 

[mofox1]

an open container? I put mine in a sealed container with an ice brick

If you want some 001, 002, 090, 099, 1318, 1217, 1728, Greenbelt, er... and some other ones... lemme know

Guessing this is to help maintain constant temps?

 

[Yob]

Nope, it'll swing more not less

 

[idzy]

I figured the ice would help cool down and the open container would allow cold to get in quicker. I guess I will put the lid on later, that's what I was thinking anyways. Otherwise the ramp will be slower I thought.

 

[mofox1]

Nope, it'll swing more not less

Ah, my bad for not reading enough of the posts. I thought this was in the freezer, not while still cooling down.

Would this be a good thing to do (for long term storage) if you have frost free fridge/freezer? Thinking it might help reduce the effect of the warm cycle.

 

[Yob]

well.. bit delayed on answering this Mofox..

Yep, great for frost free environments, i considered (still am) loading up a container with water in the test tubes, filling the container so its a 'brick' and then pulling the tubes out.. sort of like an Ice Test Tube Rack if you catch my drift?

I pulled out some San Diego Super Yeast yesterday, made a 500ml starter, put it on the stirplate this morning and the flask is full of condensation this evening, been 'frozen' (~%50) for 3-4 months

:super:

 

[mofox1]

well.. bit delayed on answering this Mofox..

Yep, great for frost free environments, i considered (still am) loading up a container with water in the test tubes, filling the container so its a 'brick' and then pulling the tubes out.. sort of like an Ice Test Tube Rack if you catch my drift?

I pulled out some San Diego Super Yeast yesterday, made a 500ml starter, put it on the stirplate this morning and the flask is full of condensation this evening, been 'frozen' (~%50) for 3-4 months

:super:

Ha. No worries... I've since caught the freeze bug anyway. Using a 3L ish polystyrene box in the freezer to counter the warm cycle. Have several samples of 4 strains frozen already, with others in the fridge.

I reckon it might be hard to get a single tube out of an ice brick unless you liberally lube it up beforehand... Just, err, make sure you do it in private. Some things are just too hard to explain.

 

[Yob]

I dunno mate, the outside of the vial is pretty smooth, I'll give it a bash and let you know.. I reckon the friction will be pretty minimal

 

[Midnight Brew]

This is a first generation top crop frozen back in January of WY1318. This was from a 50ml vial which had 20ml yeast estimated at 70 billion cells, frozen very fast with a 15% glycerin solution.

I took it out of the freezer and popped into the fridge overnight. Then put it into a 100ml starter which I shook and swirled everytime I walked past it for three days (I might need a smaller flask so I can stir plate it). Then it went straight into a 1.5L starter and this is where she's at after 24 hours.





This is from the second batch of yeast I froze. 10 months in the freezer and she's hungry for some porter.

 

[Alex.Tas]

This is a rally cool topic. Thanks Bribie for starting it and everyone else for keeping it going.

This is a first generation top crop frozen back in January of WY1318. This was from a 50ml vial which had 20ml yeast estimated at 70 billion cells, frozen very fast with a 15% glycerin solution.

When calculating yeast population growth from your defrosted starters, what sort of viability do you use?
I use http://www.yeastcalculator.com/ when building starters.

for example:
I made up a few starters of 3068 and split the slurry so that I estimate that I had 68b cells. The "production" date of the yeast I use is when it hit final gravity in the starter, which was say 15/7/14. The calculator tells me I have 46% viability after storing it in the fridge and therefore only 32.3b viable cells remaining so I base my starters off that initial quatity of 32.3b.

In your case though, the time between the final gravity of the starter and when you are restarting your 70b was spent near-frozen. So what baseline/viability do you use for defrosted yeast?

Or is this a silly question because it's an inexact art when predicting yeast populations from starters without doing a proper cell count?
Maybe i'm getting too hung up on pitching mathematically/theoretically the right quantity of yeast...

 

[Midnight Brew]

I have more or less winged it and assumed the yeast is only a little less viable then what it was when I cropped it. I presume this because once its cropped I wait a few days for it to floc down then add the glycerine solution. By this time I've lost some viability naturally with time and then I've frozen it presuming I've lost a little more. At -14C and kind of suspended in time, the viability change would be minimal.

I could be very wrong but damn that krausen looks so healthy.

 

[Yob]

Further reading..

>HERE< is the thread by Wolfy which is a slightly different method to the one discussed here..

there are other write ups not from this site like THIS one and through linked to THIS one..

also on HBT >HERE< and HERE

and HERE on BYO

 

[Midnight Brew]

Further reading..

>HERE< is the thread by Wolfy which is a slightly different method to the one discussed here..

there are other write ups not from this site like THIS one and through linked to THIS one..

also on HBT >HERE< and HERE

and HERE on BYO

Yob's above post contains more then sufficient information in those links for anyone to try it out. Well worth the time to read and try it out in my opinion.

 

[Alex.Tas]

Thanks MB. i was thinking along the lines of 90% viability. Sounds like that is similar to what you have assumed.

Yob, thanks for the links some useful info there but only one of them actually answered my question. The BYO article http://www.homebrewtalk.com/freezing-yeast.html about a third of the way down. 7.5%-15% glycerine solution seems to yield upwards of 75% viability over "several" months. That's pretty promising.

Wolfy's method involved selecting really low quantities before and after freezing and then building the population from that. While it likely worked for wolfy and is probably the best method, I would rather try and store and revive a larger population so i don't need to step up quite so many times.

The other ones gave a some good pictorial step by step guides and slight variations on the freezing technique. The http://www.ipass.net/mpdixon/Homebrew/Freezing%20Yeast.htm link gave the method in it's simplest form

So Yob and everyone else, what sort of viability do you assume from your revived samples?

 

[Yob]

I assume I can step it up even with a low viability.. a fellow member gave me a 100ml flask a month or so ago and I love the bleedin thing.. its so tiny but so perfect for an inital step up.. so

~10ml -25ml yeast to a 100ml (1030) starter (12hrs) > 500 starter (1030) starter (18hrs) > 2000ml starter (1040) (24hrs)

Plenty of time to make sure you are getting the activity behavior you are after from the starter, right smell etc..

Viability.. pretty bloody high I rekon.. some of these things go just as nuts as if they hadnt been frozen fro a year.. Ive just had a 1060 IPA drop to 1010 (WY1217) in just on 4 days I think.. I wouldnt expect better from the smack pack (though I might from a third generation 1217.. awesome..)

By the by.. had a big yeast day.. SWMBO said I was obsessed...

1272 fresh pack split into 5 vials (25ml %50 Glycerine solution 25ml Yeast/Liquid)
1450 fresh pack split into 5 vials (25ml %50 Glycerine solution 25ml Yeast/Liquid)
1056 fresh pack split into 5 vials (25ml %50 Glycerine solution 25ml Yeast/Liquid)
1217 (just to have a reset) smacked to be split and frozen tmoz.. thinking I need a generator backup.. means I have.. off the top of my head at least a dozen strains frozen off atm... some of them also have 3rd generation harvests as well.. h34r: :lol:

:beerbang:

ed: clarity

 

[barneey]

Have you guys not used yeasty balls?