orangehero

Recipes 

Any viable yeast is usually filtered out or pasteurized unless you know the beer is bottle conditioned. If it's just filtered, you could possible get a culture, but there's not going to be a lot of cells there to work with.

Brewitt

Recipes 

Most of my yeast are from beers I like and when I buy a vial of White Labs, I grow some up and freeze it as well. Most smaller microbreweries here on the west coast at least bottle condition their beer.

__________________
______________________________________
"Here's to brewers yeast, that humblest of all beasts
Producing carbon gas reducing acetaldehyde
But my friends that isn't all -- it makes ethyl alcohol
That is what the yeast excretes and that's what we imbibe."
Adam Cole (aka cadamole) http://www.youtube.com/watch?v=L6dzUOYTQtQ)

Interested in Freezing Yeast for later use in brewing?
See my article:

freezing-yeast

SamBrewer

Recipes 

Hi everybody!

It's been a while since the last time I wrote on this thread. I'm continuosly using freezing techniques learned here, and I'd like to report some considerations I made.

FREEZING PART OF LIQUID YEAST
Every time i buy a new wyeast pack I collect a part of the yeast the same day that i prepare my starter. usually I take a couple of vials with 18 ml each filled with the content of the yeast pack + 1,5ml of Glycerine. this allow you to use that kind of yeast at least 2 times. I don't want to continuosly reuse the same yeast because I don't think i can perform yeast washing in a proper way (and also because i want to be able to count the yeast cells (in a theoretical way of course). If 125ml of yeast pack has 100billions of yeast cells, each vials should have 12 billions of yeast (80% after freezing). with a couple of starters (0,5l + 1,5l with stir plate) I should end up with about 200billions of cells.

FREEZING DRY YEAST
Tried this few time with Fermentis S-23 and it work great! I only have to re hydrate yeast and fill vials with glycerine ( I use pressure cooker to sanitize everything). the only thing that I have to report is that for some reasons that I cannot explain this vials tend to produce some gas when they are opened ( I don't know why because it is just yeast and water + glycerine). So when I thaw it I have to let the gas out from the vials before putting them in the fridge. I use the fast thaw technic and then let the vials at 4°C to let the yeast settle at the bottom and remove as much liquid as I can.


Also tried to freezing yeast collected with top cropping, I've made a starter but then I decided to not using that yeast. the smell wasn't very good, beacouse I have also collected a lot of hops and proteins. I don't know if you are familar with the smell of krausen (try to skim it once ).

Thanks to everybody for the grat inforomations, this really improved my brewing process, and now that I also have a dedicated fermentation chamber I can brew every kind of beer wherever I want to!

diS

Recipes 

Where did you get this percentage?
At what temperature you freeze?

Probably from CO2 that was trapped in the slurry, when you thaw vials it fills the head space and release after opening.

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We are only 10,000 years into beer... there are thousands of years left to go!
Things are bound to change!!

Brewroom with HERMS build
Fermentation chamber and Keezer.. a.k.a. FermKeezer

SamBrewer

Recipes 

The temperature is -20°C, for the percentage I trust what is written in Brewitt's article:

"Glycerin is a cryoprotectant. It helps maintain the viability of frozen cells. We have tested final concentrations from 7.5% to 50% and found 7.5%-15% to be optimal for maintaining viability (upwards of 75% viability after several months of freezing). Lower final concentrations may also work but higher concentrations are detrimental."

of course this is just a theretical calculation but is what I use to have a "starting point" to be able to calculate starters volumes

ModlrMike

Recipes 

I found these tubes which look like the ones WL uses to supply their yeast. Would they withstand the pressure cooker sterilization process? I think so, but someone with more experience might have a different answer.

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Aging: JOAM - 1 gal

fc36

Recipes 

If you read the description closely, it very clearly states that the plastic starts to soften at around 70-80C. These are also sold w/o caps, so you'll have to buy those as well. A pressure cooker routinely gets up to 110-120C and at 10-20 psi, you may see these tubes deform and collapse under the combination of heat and pressure. Just yesterday, I tried to pour some boiling water into a PET plastic container and it melted like the wicked witch of the west. Mind you that was at 100C and 0 psi. My answer is look elsewhere. Try to get something with polycarbonate plastic or borosilicate glass. Read a few posts up from this and you'll see you don't need to freeze 50ml samples because you're still going to have to step it up twice anyways. Go with 10-25ml test tubes and you'll be happy.

Hermit

Recipes 

I heated some water in a soda bottle once to test a microwave and that was all I could find. It actually shrank pretty uniformly so we ended up with a much smaller bottle than we started with.

BBL_Brewer

Recipes 

That's why I use canning jars.

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Slots Down Brewery
Stick with the plan....not the sparge.

Never Ending Liquid Yeast - How to Farm Yeast and Freeze it.

phineascoates

Recipes 

I consider this as a good process and there are many yeast fermentation are required. First, fungi or bacteria must be present. Second, no oxygen must be present. Third, an organic compound must be present.