Do you know how to make a yeast starter? Then why not farm yeast and freeze it?

[Golddiggie]

I made A the highest yeast layer level and C the lowest for the vials. That was before I put them into the freezer, after chilling them in the fridge (standing up) for a couple of hours. I did swirl the slurry before pouring into each vial, so I'm not 100% sure why the amounts appear to be different. I'll know more after I do the next batch. I'm planning on stepping up a vial of WLP099 and freezing at least a few vials of it. Once my beaker set arrives and such that is.

Mine froze solid in under 8 hours. I have them in a small cardboard box, with foam in there to keep them standing (will take a picture later on/tomorrow). Since I don't [yet] have a small cooler that will fit in the freezer, or enough alcohol to fill it, I just chilled in the fridge first, then let them freeze as they would. I did set my freezer to it's coldest setting before this. Which gets it into the -10F to -5F range. Just a bit colder than the -20C target.

BTW, the labels are made with an Epson LW-400... I really like it.

 

[Matthewjscott]

What is a good, but inexpensive pressure cooker for sterilization?

 

[evolcoms]

Ive seen a few at local thrift stores. Just make sure they seal tight.

 

[mthompson]

What is a good, but inexpensive pressure cooker for sterilization?

Not sure what you consider inexpensive, but I have the Presto 23qt Pressure Canner (curerntly $75 + free shipping is a steal!). I think I got it for under $100 locally, plus another couple dollars for the Presto 3-piece Regulator from Amazon.

I use it almost weekly for something (brewing or food related), so ~$100 was well worth the investment. I wrap all my yeast culture stuff individually in tinfoil and run the whole load. Then they can sit on the shelf and are ready and sterile when I need them. I also can up quarts, pints, and half-pints of both 1.020 and 1.040 SG wort...pull it off the shelf and you have an instant starter.

 

[BBL_Brewer]

As far as price and quality go, I recommend the presto.

 

[Khudfly]

As far as price and quality go, I recommend the presto.

The hell with talking about yeast....who is in your avatar photo? lol

BTW, I am from Kokomo as well.

Cheers!

 

[BBL_Brewer]

Just made my first starter with the frozen PacMan yesterday evening. It was krausened up when I got up this morning. I guess 12% v/v glycerol was enough. I was a litte worried after Forkhead recanted on his original report regarding optimal concentration. Of course, I have no way of knowing what the viability was, just that the starter took off. Anyway, thought I'd share.

Cheers

 

[BBL_Brewer]

Well, I spoke too soon. The starter I made with the frozen pacman is taking forever to finish out. Stepped it up to two quarts last night (~24 hrs ago) and it's just now getting thick and krauseny. Usually by the second step things are rolling right along. I made a couple starters with fresh smack packs at the same time, same volume, and they were pretty much done this morning when I got up. Viability must have been pretty low coming out of the freeze. I'm going back to my original method which is 20-22% v/v final concentration of glycerol.

 

[fc36]

Any reason why you couldn't harvest from just about any commercial microbrew or would there have to be visible sediment on the bottom of the bottle? I'm thinking you could "innoculate" a small wort starter (250 ml or so) with about 10-25 mls of your favorite microbrew and let it sit for a couple days on a stirplate and then step that bad boy up and harvest/freeze some.

 

[BBL_Brewer]

Any reason why you couldn't harvest from just about any commercial microbrew or would there have to be visible sediment on the bottom of the bottle? I'm thinking you could "innoculate" a small wort starter (250 ml or so) with about 10-25 mls of your favorite microbrew and let it sit for a couple days on a stirplate and then step that bad boy up and harvest/freeze some.

You could absolutely do that. Just make sure to be very sanitary throughout the process and you should be good. The only reason I always start with a smack pack is because I'm not set up for plating and have no way of doing any QC. That way I always know I'm starting with yeast that is free of contamination.

 

[orangehero]

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]

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.

 

[SamBrewer]

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!:rockin:

 

[diS]

If 125ml of yeast pack has 100billions of yeast cells, each vials should have 12 billions of yeast (80% after freezing).

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

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). .

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

 

[SamBrewer]

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.

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]

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.

 

[fc36]

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.

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]

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.

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]

That's why I use canning jars.

 

[phineascoates]

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.

 

[LovesIPA]

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.

Have I had too many homebrews or does this not make any sense at all to anyone else either?

 

[fc36]

Have I had too many homebrews or does this not make any sense at all to anyone else either?

Engrish at its best.

 

[JFK]

I was given a box of pyrex 9800 18x150 rimmed tubes. Im thinking about using them to store cultures of yeast in. Will these work ok? And where can I get stoppers for them? My internet search didnt turn up anything.

+edit. It looks like size 2 stoppers. Are rubber stoppers ok to use for this application?

 

[fc36]

I was given a box of pyrex 9800 18x150 rimmed tubes. Im thinking about using them to store cultures of yeast in. Will these work ok? And where can I get stoppers for them? My internet search didnt turn up anything.

+edit. It looks like size 2 stoppers. Are rubber stoppers ok to use for this application?

They'll work, but be aware that when you're rousing the yeast from it slumber or any other times of activity, the CO2 the yeast will make may blow a few of your stoppers off from time to time.

 

[Accidic]

Amazon had some of those although I think they were a bit shorter for $7/72. Was going to buy the silicone caps for mine though. Still can be blown off but should have a little bit more forgiving pressure release.

 

[Accidic]

Also for the baby soda bottle link, they come with the caps but still hard to safely sterilize.

 

[JFK]

Thanks everyone who contributed here. I just bottled up my first attempt at creating my own yeast farm. I went to 6 places and finally found a bottle of Now 100% pure food grade vegetable glycerin. I made a 30% mixture of glycerin to sterile water, then mixed the solution with my yeast slurry left from a starter I made to pitch four 1 gallon batches @ a 1:1 ration which if my math is correct gives me a final concentration of 15%ish due to the unknown content of water in the slurry which I poured as much of the water off of it after cold crashing it overnight. It is now mixed and in my fridge to let it get nice and cold before I put it in the deep freezer tonight. How do I tell if my deep freezer has a thaw cycle? and I am assuming deep freezers are -20 degrees. I only got 1 culture because I had to pitch four batches but it is a good trial run before I go crazy with it

 

[BBL_Brewer]

Thanks everyone who contributed here. I just bottled up my first attempt at creating my own yeast farm. I went to 6 places and finally found a bottle of Now 100% pure food grade vegetable glycerin. I made a 30% mixture of glycerin to sterile water, then mixed the solution with my yeast slurry left from a starter I made to pitch four 1 gallon batches @ a 1:1 ration which if my math is correct gives me a final concentration of 15%ish due to the unknown content of water in the slurry which I poured as much of the water off of it after cold crashing it overnight. It is now mixed and in my fridge to let it get nice and cold before I put it in the deep freezer tonight. How do I tell if my deep freezer has a thaw cycle? and I am assuming deep freezers are -20 degrees. I only got 1 culture because I had to pitch four batches but it is a good trial run before I go crazy with it

Self defrosting freezers will have a thaw cycle. As long as it's not self defrosting, you're good to go. Good luck on your fist attempt.

 

[Hermit]

How do I tell if my deep freezer has a thaw cycle?

Either you have to defrost it, or not.[/QUOTE]

and I am assuming deep freezers are -20 degrees.

Zero F for home units.

 

[Accidic]

The freezer above my fridge hovers around -17 degrees F and spikes up to around 0 at periodic intervals (the frost free side of it I assume). My deep freeze only runs at -6 F but sustains it very well. That's only when it's near full. The fridge unit is rarely more than 1/4 full but the top shelf of my fridge will also freeze items solid as well. I made the mistake of storing yeast there once... Only once.