Let's Freeze Some Yeast

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Thanks Mardoo! Very helpful. I think I'll restart one to be sure in my own mind. I have a cube ready to go anyway so it would be timely anyway.
 
The next question I have for the brains trust is with the freezing.

I have limited room in the freezer and have managed to score a small polystyrene container. I tried freezing some water in it with vials with the thought I could pull the vials out and then just use the holes with ones filled with yeast but this wasn't as successful as I'd liked. Couldn't easily get the temporary vials out and then put the new ones in and now checking they are hard too.

Is the polystyrene container enough to maintain again the defrost cycle or what does everyone else do?
 
I just chuck a gel ice pack or two on top of the vials. I've tried a number of mediums like you did with ice, and, so far, all have been more trouble than they're worth. A hell ice pack on top of the vials inside a closed container has worked great for me. If the container is insulated, even better.
 
Having now banked 10 strains, tonight I'm finally going to revive some (WLP029).

If I'm looking at building to 270bn cells, what's the best way of figuring out how to get there and how many cells I've got at any given point? Is the only realistic way by doing a starter and then looking at the amount of slurry in my flask to try to guesstimate how many cells I end up with?
 
Use the CaptainBrew pitch rate calculator. It allows you to do up to three steps-up. There are various options for aeration. If using a stir-plate I recommend the Kai Troester setting. People differ on this. That gives me an amount that always gives me clean ferments that don't stall. You can also calculate DME or LME amount to use, if you use it.

https://www.captainbrew.com/yeast-pitch-rate-and-starter-calculator

The only way to know count and health for sure is to use a high-powered microscope and a cytometer to count by hand and then estimate up. For homebrewing purposes you don't need to geek that hard, unless YOU need to geek that hard. I may do so in the future, but I just use broad volumetric estimates and experience to work out yeast count and health.

For the first step up, use 1.020 wort, just to give the yeast a gentle wake up. For ales I can usually get to pitching volume in two steps. You can adjust all those settings in the Captain Brew calculator, as well as initial pitch, which I estimate as % of original yeast pack into the vial - 20% to allow for death from freezing, I use the number of weeks from the production date to when I froze to estimate viability.

It's something you'll grow used to as you do it over time. Hope that all makes sense. Open up the calculator and you'll see the settings I mention.
 
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Hugh Grant or Hugh Jackman powered microscope?

:)

Now I have started freezing yeast I have wondered the same thing about how to tell how much is in there in the first place and so how many steps to use.

I have been using 200ml @ 1.020, 500ml @ 1.040 and 2l @ 1.040 because I read it somewhere.
 
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I have been using 200ml @ 1.020, 500ml @ 1.040 and 2l @ 1.040 because I read it somewhere.
Depends on what sized vials you are using, how much yeast solids are in the vial, and how old it is.

For a reasonably fresh, 1/2 yeast solids 15ml vial, I reckon that is on the money (anecdotal evidence only). Should also be good for older 50ml vials too.

If there is less yeast solids in the 15's, or they are getting on in age, then I'd recommend using more than one vial.

I've just pitched into 48L of a marzen. Started off at only 10ml solids of 1 year old WLP838. Built up to 11L using 6 steps over about 2 weeks, then 1 week cold crash to decant spent beer so I can pitch just the yeast. 10L of the total was for pitching, the other litre was to put back into the yeast bank.

The lager is currently frothing like mad and making full use of the blow off tube.
 
Depends on what sized vials you are using, how much yeast solids are in the vial, and how old it is.

For a reasonably fresh, 1/2 yeast solids 15ml vial, I reckon that is on the money (anecdotal evidence only). Should also be good for older 50ml vials too.

If there is less yeast solids in the 15's, or they are getting on in age, then I'd recommend using more than one vial.

I've just pitched into 48L of a marzen. Started off at only 10ml solids of 1 year old WLP838. Built up to 11L using 6 steps over about 2 weeks, then 1 week cold crash to decant spent beer so I can pitch just the yeast. 10L of the total was for pitching, the other litre was to put back into the yeast bank.

The lager is currently frothing like mad and making full use of the blow off tube.

So much to learn :). Love this hobby.

11 litres? That's one hell of a flask! Where does one by an 11litre flask and then I would love to see the stir plate! ;)
 
So much to learn :). Love this hobby.

11 litres? That's one hell of a flask! Where does one by an 11litre flask and then I would love to see the stir plate! ;)

LOL. End amount was in multiple flasks. Required significant planning to ensure I had the right flasks at the right time...

I have a 250ml, 500ml, 2 x 1L, 2 x 3L and 1 x 5L flasks + a few other bits and bobs. Missus reckons it a bit of a mad scientist's lab, not inclined to disagree.

Edit:
Just for laughs... here is the step up schedule:
21-Jul: pitched 10ml yeast solids -> 300ml(500ml Flask) @ 1.020
23-Jul: 300ml(500ml) -> 500ml(1L) @ 1.038
25-Jul: 500ml(1L) -> 1L(1L) @ 1.038
27-Jul: 1L(1L) -> 2L(3L) for next step & 1L(1L) for vials @ 1.038
29-Jul: 2L(3L) -> 5L(5L) for pitch & 1L(1L) for next step @ 1.038
31-Jul: 1L(1L) -> 2.5L(3L) & 2.5L(3L) @ 1.038, Cold crash 1L(1L) for vials
04-Aug: Cold crash 5L(5L) & 2 x 2.5L(3L)
08-Aug: Packaged 1L(1L) into 7 x 15ml vials ~6ml yeast solids each
12-Aug: Decanted spent starter liquid, vitality starter for 4hrs prior to pitch using wort from cubes, yeast spread equally over 2 x 3L flasks.

All up would have used ~1.5kg of DME... about $9 worth at bulk pricing. Well worth the effort as long you enjoy the process.
 
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The 11L cubes from DJ_L3thAL are great for doing big step ups. I've gone from 2x 3L grows on the stirplate to an 11L non-stirred ferment to get the amount of yeast necessary for a heavy pitch.
 
The 11L cubes from DJ_L3thAL are great for doing big step ups. I've gone from 2x 3L grows on the stirplate to an 11L non-stirred ferment to get the amount of yeast necessary for a heavy pitch.
Nice, you get to drink - or more importantly, enjoy - your "starter".
 
Yeah, I'm about to do the Westy 12 step up (well, after an IBA ferment) on a hoppy wheat featuring Huëll Melon. I'll rack off the yeast cake for the dry hop. Can't wait!
 
LOL. End amount was in multiple flasks. Required significant planning to ensure I had the right flasks at the right time...

I have a 250ml, 500ml, 2 x 1L, 2 x 3L and 1 x 5L flasks + a few other bits and bobs. Missus reckons it a bit of a mad scientist's lab, not inclined to disagree.

Edit:
Just for laughs... here is the step up schedule:
21-Jul: pitched 10ml yeast solids -> 300ml(500ml Flask) @ 1.020
23-Jul: 300ml(500ml) -> 500ml(1L) @ 1.038
25-Jul: 500ml(1L) -> 1L(1L) @ 1.038
27-Jul: 1L(1L) -> 2L(3L) for next step & 1L(1L) for vials @ 1.038
29-Jul: 2L(3L) -> 5L(5L) for pitch & 1L(1L) for next step @ 1.038
31-Jul: 1L(1L) -> 2.5L(3L) & 2.5L(3L) @ 1.038, Cold crash 1L(1L) for vials
04-Aug: Cold crash 5L(5L) & 2 x 2.5L(3L)
08-Aug: Packaged 1L(1L) into 7 x 15ml vials ~6ml yeast solids each
12-Aug: Decanted spent starter liquid, vitality starter for 4hrs prior to pitch using wort from cubes, yeast spread equally over 2 x 3L flasks.

All up would have used ~1.5kg of DME... about $9 worth at bulk pricing. Well worth the effort as long you enjoy the process.

Do you chill down between steps or just tip from one into the other?
 
I've done and do it both ways, mostly depending on impatience. I'd say not chilling results in the yeast being slightly faster off the mark in the final ferment. In reality though, other than the time it takes to do the rest and chill (72 hours between steps, the way I do it) the difference seems negligible.

If I'm growing up the yeast to freeze it, I do the rest and chill, as (according to the Yeast book) the rest develops glucose reserves, and the chill develops trehalose reserves, both helpful for the post-freeze kickstart.

If I do tip, I check final gravity of the starter steps so I can account for dilution to ensure I stay close to the gravity goal for the follow-on starter.

Mofo?
 

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