Let's Freeze Some Yeast

[Bruer]

this... ^^^^^^

Im usually at about %25 now, just coz its easy numbers to do

So that's 25% glycerin and 75% yeast slurry?

 

[Bruer]

How can I sterilise the glycerin without an autoclave/pressure cooker. I have plastic tubes.

 

[Yob]

Microwave

 

[Yob]

How can I sterilise the glycerin without an autoclave/pressure cooker. I have plastic tubes.

Wait.. Wait.. You have test tubes?

 

[Bruer]

Wait.. Wait.. You have test tubes?

Plastic centrifuge tubes.

 

[Yob]

Perfek

Microwave in a pyrex jug if you have one, half water and half glycerine... then 25ml in each tube.

Top up with yeast slurry, fridge 36 hours, freeze.

 

[Bruer]

Perfek

Microwave in a pyrex jug if you have one, half water and half glycerine... then 25ml in each tube.

Top up with yeast slurry, fridge 36 hours, freeze.

Cool... I figured if it was good enough for doing with gelatin, it was good enough for the glycerine.

And just soak the tubes in starsan before filling?

 

[Yob]

Cool... I figured if it was good enough for doing with gelatin, it was good enough for the glycerine.

And just soak the tubes in starsan before filling?

thats what I do mate, yep

 

[Nullnvoid]

How long in the microwave?

 

[Yob]

If it boils over... It's too long

 

[Moad]

I've just read this entire thread for the second time and am inspired to give it a go, gives me a good excuse to buy a pressure cooker for use on other brewing applications.

Planning on pre making various strength starter wort jars and storing to make the starter process quicker and easier as well.

Do you guys typically keep a strain going for a few generations and then build up another frozen sample. Or do you capture each time? I can see if you captured each generation you could build up a huge bank quickly and not have to buy yeast for a long time.

 

[Yob]

I typically split and bank first generation into 5, then when I use it and it gets cracking, say third gen, I'll wash and save that as well.

When we talk generations, we say third but it's really about 18-20, each ferment will generate about 6-8 budding cycles.. But yeah.. Whateves.. We all know what we mean I think..

 

[Moad]

I'm following, just trying to work out how to use it effectively... bit of a case of RDW....

So first build a starter and split that out into 1st gen vials. Then for each vial build a starter and split that out again (25 vials of 3rd or 4th gen including steps). That should be enough for a strain for me as I will use slurry for a few brews (from 20-120L batches) So I could essentially get 100 batches out of 1 pack of yeast. incredible

Whats the longest you have had yeast stored and revived now? I believe my freezer is frost free, what is the process of the "salt water ice"? Literally making ice with salt water? I was thinking I could use zip lock bags with salt water and freeze them then pack them in insulated tupperware style container with the yeast.

 

[Mardoo]

You can go straight into vial from the manufacturer's package, or if you wish make a starter. From starters, I haven't seen the results of generational changes in the yeast during fermentation like I have seen it with fully fermented out yeast. For example a third generation yeast only grown in starters doesn't seem to show the same changes that a yeast fermented out to the third generation will. Does that make sense?

So you can save yeast from pack or starter and use that as first generation. After you've fermented it out three times freeze it as third generation. I've done that with 1469, which shows increased complexity in later generations, to my palate.

 

[Moad]

nice thanks Mardoo, makes sense.

So when starting up a vial I can capture some and refreeze and it wouldn't have as much drift as capturing some after fermenting out.

It is a whole hobby in itself!

 

[Yob]

it is.. and just as consuming as the parent hobby..

 

[Mardoo]

Yep, on the vial and the hobby.

I've been wanting to geek hard and save out samples of 5 generations of the same yeast and ferment each generation on the same wort. Time permitting…HAH!

 

[mofox1]

nice thanks Mardoo, makes sense.

So when starting up a vial I can capture some and refreeze and it wouldn't have as much drift as capturing some after fermenting out.

It is a whole hobby in itself!

That's what I do... build up starters to re-freeze while I'm building up to pitch into the next brew.

My process as follows:
- build up to a 2L starter (which is 3 steps in itself if coming from a single 15ml vial)
- crash chill
- decant
- pitch half into a new 2.5 / 3L starter (to pitch into wort)
- store the rest in vials for freezing

I prefer this method to yeast rinsing because the yeast is super fresh and (less important but more practical) I'm usually not organised enough to package beer AND capture yeast at the same time.

 

[Yob]

Im a little different..

depending on the age of the sample, and Ive still got a few from my first freeze that fire up with no issues, I'll do a 1lt starter (1.020) and then a 3lt starter (1.040), when that's going nuts, I'll pitch 2.5L to brew and tip 500ml into another flask and allow to settle out so that the yeast build their glycogen and trehalose reserves up, then split freeze.. and/or rinse and split if it was a particularly impressive ferment.

many many ways to beat that kitten to death.. try them all and work out what suits you best.

 

[Moad]

awesome exactly what I was after thankyou gents.

Waiting on some vials to arrive and then I'll get my yeast on