Let's Freeze Some Yeast

[kcurnow]

ImageUploadedByAussie Home Brewer1446185281.580852.jpg

now thats a steriliser!!

 

[MartinOC]

VP, that is a thing of beauty & you're definitely well on the track for success.

 

[Yob]

a peak inside the freezer reveals...




addiction

 

[tateg]

Yep, salt ice will be colder, I initially used a cluplock box and gaffe taped Styrofoam to it... Worked but I ended up dedicating space in the deep freezer... Better

Just how much salt in the water are we talking ? Simple as just crush and place abound the vials?

 

[VP Brewing]

a peak inside the freezer reveals...

Vials.JPG

addiction

So many choices!

 

[Yob]

Just how much salt in the water are we talking ? Simple as just crush and place abound the vials?

Make a bunch of ice cubes

 

[MartinOC]

I'll see your selection & raise you just a couple of the bags I just pulled from my freezer:



All opened once only to decant excess liquid & add glycerine.

All packaged within BB-date. Free.

 

[Mardoo]

Careful folks, low-swingin' dick around here

 

[danestead]

Have any of you guys checked viability of your frozen yeast with a microscope? I just had a vial of mine checked and it revealed 99.9% dead and munted yeast. Very few live cells.

Wyeast 1217 West Coast IPA
25% glycerine, 25% water, 50% wyeast poured straight from a 2 week old packet
Stored at -20 degrees
It was in solid form however I think it had liquidised at some stage because layers are now visible
1 year in the freezer

 

[MartinOC]

High-swinging if you don't mind.......

 

[mofox1]

Have any of you guys checked viability of your frozen yeast with a microscope? I just had a vial of mine checked and it revealed 99.9% dead and munted yeast. Very few live cells.

Wyeast 1217 West Coast IPA
25% glycerine, 25% water, 50% wyeast poured straight from a 2 week old packet
Stored at -20 degrees
It was in solid form however I think it had liquidised at some stage because layers are now visible
1 year in the freezer

Great feedback Dano... did you have any samples with a higher glc % that you could get checked?

I usually go around 30 - 35% glc, samples are usually only-just-not-quite-frozen at these levels... the whole idea about adding glycerine is to be able to reduce the temp (and therefore the attrition rate with higher temps) while not subjecting your yeast buddies to cell wall destroying water crystallization death (there is a word for when then cell wall is ruptured and the contents are spilled out, but after eleventy or something beers I can't remember it).

I haven't got it right with all of them, probably about half still look "frozen" which is probably why that first starter step is so laggy and uneventful... would be handy to see if there is an increase in viability (and observations on cell health / mutations) with higher glc rates.

 

[danestead]

Great feedback Dano... did you have any samples with a higher glc % that you could get checked?

I usually go around 30 - 35% glc, samples are usually only-just-not-quite-frozen at these levels... the whole idea about adding glycerine is to be able to reduce the temp (and therefore the attrition rate with higher temps) while not subjecting your yeast buddies to cell wall destroying water crystallization death (there is a word for when then cell wall is ruptured and the contents are spilled out, but after eleventy or something beers I can't remember it).

I haven't got it right with all of them, probably about half still look "frozen" which is probably why that first starter step is so laggy and uneventful... would be handy to see if there is an increase in viability (and observations on cell health / mutations) with higher glc rates.

Unfortunately no I havent got any with any different glycerin contents. Ive only done the 1 batch.

My freezer used to be set on -15 deg but the vials were liquid at that setting so I upped it to -20 to freeze them solid with the sole purpose of stopping the settling out and layering of yeast. Why? I dont know. Just because. Maybe liquid form would of been better at -15 however in this thread I think people have been successful with both liquid and solid versions.

Id really like to hear some more scientific evidence of viabilities rather than yes it fired up quick etc etc.

 

[Yob]

What's the process you use to freeze? Do you let them sit in the fridge for a few days prior to the deep freeze?

My ratio's are roughly the same and there's no way I get that much death, the starters fire up too fast.

 

[Midnight Brew]

Have any of you guys checked viability of your frozen yeast with a microscope? I just had a vial of mine checked and it revealed 99.9% dead and munted yeast. Very few live cells.

Wyeast 1217 West Coast IPA
25% glycerine, 25% water, 50% wyeast poured straight from a 2 week old packet
Stored at -20 degrees
It was in solid form however I think it had liquidised at some stage because layers are now visible
1 year in the freezer

How did you freeze your yeast? Did you add straight to the freezer? Did you bring them down to below zero then freeze?

I ask this because a fellow brewer, Grainer, pointed me in the right direction to freeze as quickly as possible. Ice bath of salt water and throw the vials in works for me.

First batch I froze I slow froze them and killed them all. I tried Grainer's ice bath suggestion and it worked and those yeast are still viable 18+ months later. (I use a 15% Glycerine solution)

 

[danestead]

How did you freeze your yeast? Did you add straight to the freezer? Did you bring them down to below zero then freeze?

I ask this because a fellow brewer, Grainer, pointed me in the right direction to freeze as quickly as possible. Ice bath of salt water and throw the vials in works for me.

First batch I froze I slow froze them and killed them all. I tried Grainer's ice bath suggestion and it worked and those yeast are still viable 18+ months later. (I use a 15% Glycerine solution)

I can't actually remember 100% how I froze them however I do remember reading that freezing them as quickly as possible is beneficial. I would take a guess and say I did an ice bath and then put them in the freezer. I also remember setting my freezer to its max of -30 for the first day, then let it go back to its normal setting of -20.

Having said that, I think I've read that guys on here like Yob fridge them for a day then freeze them.

I guess the main point of my post regarding the 99.9% fatality of my frozen yeast is to find out who has actually taken a more scientific approach like looking at the yeast under a microscope to see what the state of them are. Considering the fatality rate my batch has had, I don't think that it satisfies me enough anymore to assume other peoples yeast have great viability and health because they have said their starters are firing up well and attenuating as per normal. I want to see the results of their freezing attempts under a microscope before I go ahead and freeze more yeast.

 

[Yob]

Bring round the microscope. I'm interested now myself

 

[kcurnow]

here is my microscope, complete with 5mp lens camera. I have the haemocytometer just need to get J-count (automated cell counting software) loaded on a computer and then get some time to fire up one of my frozen batches and do some viability tests. As well as move to QLD. Sooooo it might be a while.

 

[Yob]

So can I bring a vial on Tuesday?

 

[Mardoo]

Selling the mic???

 

[kcurnow]

Selling the mic???

nope!!