Let's Freeze Some Yeast

[Mardoo]

That's exactly what I've been doing. It's only taking two steps, which has been a surprise. Not sure whether it's rushing it. Wasn't intending to do two steps. My small flask was dirty so I just did a 500ml first step followed by 2L. I've been getting just what I need for a single pitch. Only done it twice.

Hard to tell whether viability has been affected, as the wort I've fermented the pitches on had a very unpredictable aspect in its production. Any opinions or information on the effect of two steps vs three?

 

[Lord Raja Goomba I]

And what ratio became the norm?

Water to Glycerine ratio (50/50 water to glycerine?). Or expressed as 37.5/37.5/25 ratio of water/glycerine/yeast slurry? Just for my accountant pedantic brain.

I've just grabbed a 1L for $7.95 plus delivery evilbay vegetable glycerine amount and will do this on the weekend.

(BTW I absent mindedly froze some WLP001 without doing this, so might resurrect it and see if it fires and then can be split. Any thoughts?)

 

[kaiserben]

I've just grabbed a 1L for $7.95 plus delivery evilbay vegetable glycerine amount and will do this on the weekend.

Could you provide the link for this?

 

[Lord Raja Goomba I]

Could you provide the link for this?

http://www.ebay.com.au/itm/191613432703

 

[malt junkie]

LRG, I do 50/50 glycerine/ water to half vial and top the rest with yeast in a 50ml vial. works for me!

 

[Lord Raja Goomba I]

LRG, I do 50/50 glycerine/ water to half vial and top the rest with yeast in a 50ml vial. works for me!

Sweet, thanks heaps.

Love to hear more confirmation stories.

 

[Yob]

Same ratio for me, better, ot least less harsh environment and the yeast seem to be able to expel the glycerine faster than a higher ratio

 

[Lord Raja Goomba I]

Good, so that ends up being a 25/25/50 ratio of water, glycerine and yeast?

 

[Midnight Brew]

And what ratio became the norm?

Water to Glycerine ratio (50/50 water to glycerine?). Or expressed as 37.5/37.5/25 ratio of water/glycerine/yeast slurry?

(BTW I absent mindedly froze some WLP001 without doing this, so might resurrect it and see if it fires and then can be split. Any thoughts?)

Originally I used a 10% ratio of glycerine. It works great when frozen correctly. At 10% you need to crash the yeast to below freezing temperatures as fast as possible. If you just pop it in the freezer and let it freeze slowly the cells are more likely to shear. I had a conversation with Grainer about it a few years back when I first started freezing. There was another reason but I cant quiet recall. Grainer has a background in microbiology.

At 25% the cells dont actually freeze but more or less stay suspended in time. Less chance of shearing the cells. And just about everyone that has used it at this percentage has reported back with good results.

As for your WLP001. I doubt it will resurrect but please report back your results.


Get ready to dive into the hobby that is yeast farming. May your yeast be fruitful and multiply.

 

[Lord Raja Goomba I]

Originally I used a 10% ratio of glycerine. It works great when frozen correctly. At 10% you need to crash the yeast to below freezing temperatures as fast as possible. If you just pop it in the freezer and let it freeze slowly the cells are more likely to shear. I had a conversation with Grainer about it a few years back when I first started freezing. There was another reason but I cant quiet recall. Grainer has a background in microbiology.

At 25% the cells dont actually freeze but more or less stay suspended in time. Less chance of shearing the cells. And just about everyone that has used it at this percentage has reported back with good results.

As for your WLP001. I doubt it will resurrect but please report back your results.


Get ready to dive into the hobby that is yeast farming. May your yeast be fruitful and multiply.

Thanks bud. Looking forward to this - fun wise and cost wise (and having a good bank of something other than dried yeast).

I've done a bit of research and apparently, there may be 10% or so of viable yeast in a frozen smack pack. In the US, they have this stuff called snow and sometimes they get stuff delivered and it's frozen because of it. So a starter and they can get it moving.

I wish we got snow. I hate the heat.

 

[Mardoo]

Again, another for the 25/25/50 ratio. Works the best of the the three I've tried, being 10% glycerine, 25%, and 50%. Don't bother with 50%...

 

[Yob]

Anecdotally, the %50 is harder for the yeast to expel, seems like it takes longer for the yeast to fire up in the starter, but it stays liquid and doesn't freeze solid, I feel the trade off to a %25, while it does go solid is a better mix with no noticeable drift after over 2 years in the deep freezer. Last count I had over 180 vials and over 30 strains...

 

[Moad]

another 25/25/50% here. I don't treat my yeasties too well, They are just in a container in a frost free freezer with one of those freezer gel packs thrown in. I have had no issues whatsoever with spinning up yeast (granted only up to 8 or 9 months so far) and achieving great fermentation indiscernible from starter made straight from smack pack.

This has possibly been the greatest thread I have been involved with in my AHB career! Thanks to Yob especially for continued contribution

p.s when are the vaults going into full production?

 

[Yob]

I'm deciding over the vault walls, will post in the other thread as to the direction.

 

[MartinOC]

I'm quivering in anticipppppppation!

 

[Yob]

it's terribly addictive...

its also a fascinating sub hobby to brewing.. and even a hobby in its own right...

 

[malt junkie]

But if you weren't brewing what good would yeast freezing be? Ok you could start baking but how many strains could you actually bake with?
I feel a yeastperiment may be on the cards. Hefe-danish anyone?

 

[peteru]

Beer yeasts are too slow for most baking needs. I tried making pizza with Cooper's kit yeast. After making one biscuit with pizza toppings, I just got out the dried bakers yeast, teaspoon of sugar and some water and fixed up the dough. Night and day. The rest of the pizzas turned out fine.

 

[Mardoo]

Actually many brewpubs in the States use hefeweizen yeasts for their pizza dough. Maybe it's the massive krausen ones that would work better.

 

[Schooner_downunder]

Can someone let me know if I have stuffed up something with some yeast I recently tried to freeze. Should Glycol be on top or bottom?

My process was I started with a White labs pack of WLP001 (California Ale) and a 500 ml starter for 12 hours, then stepped to 1.5 liters and ran for 36 hours to high Krazen. Put into the fridge overnight to settle yeast decanted and put a 50/50 mix into 50 ml tubes.

My fridge goes down to - 23 C. Here is a pic of the yeast. I may be paranoid but is the vegetable glycol suppose to be sitting on the bottom and the yeast on the top?