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

Brewitt said:

Sounds right. Your math and science are not as bad as you think. 20 mls will be fine if you use yeast in the state you suggest and grow a couple liter starter for a day. Have fun!

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Thanks! This thread and brewing in general have really allowed me to improve in the areas of math and science, but it's still a struggle for me. I'd been out of school for a lot of years before I started brewing and it's been a great way to get my brain working again.

I can't wait to get my first batch of yeast in the freezer. I'm pretty excited about the whole venture.

And, yes, I plan on making starters each time I brew. I only brew 3.5 gallon batches, so I usually don't have to make quite as large a starter as many folks.

Thanks for the assistance.

How long would it take to freeze one of these in a chest freezer in the alcohol in a cooler? I only have one cooler and it can only fit 2 jars in at a time and I don't want to bring them out too soon and directly into the freezer.

theveganbrewer said:

How long would it take to freeze one of these in a chest freezer in the alcohol in a cooler? I only have one cooler and it can only fit 2 jars in at a time and I don't want to bring them out too soon and directly into the freezer.

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How many jars do you have? If it's going to take too long, I would just put your jars into the freezer and not worry about the alcahol thing. Granted it might increase viability, but it is not necessary. I've been freezing without an alcahol bath. I don't have room in my chest freezer for a cooler large enough to hold the amount of jars I normally freeze.

As BBL_Brewer says, the alcohol bath is an "add on" that slows the freezing process and stabilizes the temperature. If you have a non-frost free freezer, then it becomes much less important because the cycles involved in keeping the freezer frost-free are not a problem. Quick freezing vs slow freezing definitely affect viability but, if you are growing a starter, the effect of loss of viability becomes negligible. Perhaps during my upcoming revision of the article, I should emphasize which things are critical and which are simply optimal, or as my wife likes to tell our kids, "there's nice to have and need to have".

I decided to give the yeast another chance to replicate on Saturday evening (put on some Barry White and then finished off with some Isaac Hayes ). Got the flask in the fridge (after about 12-14 hours on the stirplate, it was done) to cold crash/compact. Planning on removing it tomorrow in order to mix up the slurry and glycerine solution. I might aim for 500ml total volume (easier to just split my previous calculations in half) and get them vials filled and chilled.

I plan on brewing with one of the vials at the start of the year (provided the world doesn't end first :rockin. Trying to decide if I should store a vial in the fridge, or freeze it all. I don't have a pressure cooker, so it might be better to freeze it all... Thoughts on that? I'm checking to see if any family members (close enough to where I live) has one, or not. Maybe it would be worth picking up a small one for things like this... Hmmmmm

Golddiggie said:

I decided to give the yeast another chance to replicate on Saturday evening (put on some Barry White and then finished off with some Isaac Hayes ). Got the flask in the fridge (after about 12-14 hours on the stirplate, it was done) to cold crash/compact. Planning on removing it tomorrow in order to mix up the slurry and glycerine solution. I might aim for 500ml total volume (easier to just split my previous calculations in half) and get them vials filled and chilled.

I plan on brewing with one of the vials at the start of the year (provided the world doesn't end first :rockin. Trying to decide if I should store a vial in the fridge, or freeze it all. I don't have a pressure cooker, so it might be better to freeze it all... Thoughts on that? I'm checking to see if any family members (close enough to where I live) has one, or not. Maybe it would be worth picking up a small one for things like this... Hmmmmm

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I'm not sure why you don't want to refrigerate one of the vials because you don't have a pressure cooker. Because it wasn't sterilized? If that's the case, you'll have the same situation on your hands when you thaw them out. Anyway, I would treat the unfrozen vial the same way you would any other liquid yeast. I did the same thing recently when I made up a batch of freezer yeast. I kept out six jars for brew day. They sat around for almost two weeks in the frige and then I made starters with them. I've actually wondered if sitting for long periods of time in the presence of glycerol is detrimental if the curltures aren't frozen. Any thoughts on that?

Checked and no one in the family has a pressure cooker. So best I can do is either boiling things (normally) or just a good soak in Star San solution. Can't justify spending the funds on a pressure cooker, when I'll use it infrequently at best.

As long as I'm not setting myself up for failure, I'll use either the Star San soak, or boiling temps with the vials (and equipment).

Golddiggie said:

Checked and no one in the family has a pressure cooker. So best I can do is either boiling things (normally) or just a good soak in Star San solution. Can't justify spending the funds on a pressure cooker, when I'll use it infrequently at best.

As long as I'm not setting myself up for failure, I'll use either the Star San soak, or boiling temps with the vials (and equipment).

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Won't work for plastic caps, but anything glass can be sterilized in the oven. 350 for 1 hour. I used to sterilze my bottles that way. As for the star san, it should be good enough. Just give it some extra contact time and you should be fine. I was short 8 or 9 nine jars on my last batch, so I soaked some in star san myself.

Edit

Word of caution if you sterilze in the oven. When using non tempered glass, you need to warm slowly and cool slowly or you risk cracking the glass. I've never cracked a bottle though and I've sterilzed quite a few that way.

BBL_Brewer said:

I've actually wondered if sitting for long periods of time in the presence of glycerol is detrimental if the curltures aren't frozen. Any thoughts on that?

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Although I can't speak from experience on this, I would think that leaving cells sitting in the frig in 10-15% glycerol would be fine. An experiment comparing them would be useful but I don't think there will be significant detrimental effects. If there is oxygen around the yeast may metabolize is very very slowly which means they might not be in the very best state for long term storage but I'm not sure that would pose a significant problem.

Looks like I'll be conducting an adhoc experiment then. Star San to make safe (using plastic vials here) and such. Will have to see how thick the yeast cake is in the flask tomorrow. If it's large enough to have making the 1L mix, then I will. Otherwise I'll scale it back to 500ml and go from there. That might actually be better anyway, since I only have about 12-18 of these vials (less than 18 actually since I think I gave one to my brew-buddy full of yeast nutrient for use in a mead)...

Brewitt said:

Although I can't speak from experience on this, I would think that leaving cells sitting in the frig in 10-15% glycerol would be fine.

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That's kind of what I figured, but since it seems that glycerol can be cytotoxic (proven by the lower viability of cultrues frozen in higher concentrations of glycerol) it stands to reason that it could affect the viability of unfrozen cultures if left for an extended period of time.

What's your thoughts on glycerine levels and time, in the fridge, where you won't be safe anymore? I could be 3-8 weeks from using one of these vials (if left in the fridge)...

Golddiggie said:

What's your thoughts on glycerine levels and time, in the fridge, where you won't be safe anymore? I could be 3-8 weeks from using one of these vials (if left in the fridge)...

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I can't really comment on that since my comment is really just a guess. Unless there is a reason to do it I probably would error on the side of caution and not add it unless your procedure necessitates it. At least until someone tests it out.

I'll use it by about the middle of January (about 4 weeks in the fridge before I start making my starters with it) in my first MO SMaSH batch of the new year. SMaSHing in 2013. :rockin: If things go according to plan, I'll brew it up first weekend in 2013.

Alright, after several delays I finally got the glycerine and yeast mixed up and got it into vials. I'm giving them a few hours in the fridge before I'll send them into the freezer. Due to how many vials I have on hand, I decided to just mix up 500ml. Got 12 vials this way.

I figured a couple of hours in the fridge would help me to see how much yeast made it into each vial. Since this is a very flocculant strain, I had to keep swirling between pours. I am looking at getting a 1L flask/beaker in order to measure and mix better. I figure that with a beaker, I could put it back on the stirplate between pours to get it all mixed up again. Plus, with the 1L size it should have graduation marks that will be of more use/help.

Golddiggie said:

Alright, after several delays I finally got the glycerine and yeast mixed up and got it into vials. I'm giving them a few hours in the fridge before I'll send them into the freezer. Due to how many vials I have on hand, I decided to just mix up 500ml. Got 12 vials this way.

I figured a couple of hours in the fridge would help me to see how much yeast made it into each vial. Since this is a very flocculant strain, I had to keep swirling between pours. I am looking at getting a 1L flask/beaker in order to measure and mix better. I figure that with a beaker, I could put it back on the stirplate between pours to get it all mixed up again. Plus, with the 1L size it should have graduation marks that will be of more use/help.

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I put mine back on the stir plate for a few to mix it up good and then just swirl inbetween pours. I use pretty flocculant strains most of the time and haven't noticed much difference between the packed cell volumes when I thaw them. The main thing is to bust up all those big clumps after you cold crash. As long as you get a good homogenous mixture going with the stir plate before hand, you shouldn't have any problems in the time it takes to fill containers.

I need to get the smaller glass hardware. Just looked at the vials in the fridge and even though I mixed it up on the stirplate, and swirled between pours, the flasks do not all have the same amount in them.

This is my first yeast freeze, so I'm going to ask this one... Will I be able to tell the yeast level, same as in the fridge, while it's still frozen?

I'm thinking about using a sharpie, or tape, to mark where the yeast level is on each vial. That way I'll have a better idea of what's in each one without thawing them out. Whatcha think??

Golddiggie said:

I need to get the smaller glass hardware. Just looked at the vials in the fridge and even though I mixed it up on the stirplate, and swirled between pours, the flasks do not all have the same amount in them.

This is my first yeast freeze, so I'm going to ask this one... Will I be able to tell the yeast level, same as in the fridge, while it's still frozen?

I'm thinking about using a sharpie, or tape, to mark where the yeast level is on each vial. That way I'll have a better idea of what's in each one without thawing them out. Whatcha think??

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I'm surprised it varies that much with all the effort you went to keeping it mixed. Anyway, I would just take note of the slurry volume when you thaw it and then plug that into a yeast calculator. I don't see the advantage of marking up the vials. Plus it would need to be something you could easily remove if you plan to reuse them.

I think the next run will go much better. I'm getting ready to order some additional supplies that will make things easier on me. Like graduated beakers in sizes that make sense (it's a 5 beaker set).

I will say, glycerine is ugly stuff coming out of the bottle. Consistency of thick whale snot. But it moves fast.

I'm looking to donate a few of these vials to members of the HBC I'm still signed up with. Got one person to reply to my message so far (sent early this week). If no one else takes them, well sucks to be them (if they like the strain). I'll offer up vials to the new HBC I'll be joining at the start of the year.

Thinking that maybe I'll leave a couple of the lower volume vials in the fridge and use them in a starter once my other supplies arrive. Then I can freeze more yeast. :rockin:

Back onto my 2nd strain for freezing. I'm wondering what I should do to get even more than I have now. I have about 550 billion cells in my largest starter. Should I split the batch into 4 parts and go up to 4 liter starters with each of them? That'd give me like 2 trillion cells, correct? Any harm in stepping them up like that?

theveganbrewer said:

Back onto my 2nd strain for freezing. I'm wondering what I should do to get even more than I have now. I have about 550 billion cells in my largest starter. Should I split the batch into 4 parts and go up to 4 liter starters with each of them? That'd give me like 2 trillion cells, correct? Any harm in stepping them up like that?

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That should give you ~2 trillion with a stir plate. And no, I don't think there's any harm in doing it that way. I basically do the same thing. I usually grow up 500 billion, then split that into 5 parts and grow another 500 billion each.

I just used some good white tape on the caps to 'grade' each vial then put them all into the freezer. No point in putting it off any longer. I did leave them as close to standing up as possible (used a box with styrofoam in it to both pad and keep them mostly vertical.

A+ is 1/2 a vial of yeast/solids or more.
A is just under 1/2 to just over 1/3 a vial of yeast/solids
B is between 1/3 a vial and 1/4 of yeast/solids
C is under 1/4 a vial of solids, or dark solids only (compared with the other vials).

Not sure what the darker stuff is, since this wasn't washed yeast, but kept after a starter then stepped up a couple of times. I plan on using the C vials first, to see if I can get viable yeast from them. A small starter should give me that answer pretty easily. I'll probably make another starter from one of the A vials, step it up a few times, and freeze the results from that one. Especially after the gear I'm looking to get arrives.

BTW, the vials hold 45ML of liquid in them. At least that's what they hold to where they won't burst when frozen.

I hope it doesn't matter that the yeast layer was more settled in the vials before I froze them. It would really suck if that buggered the entire thing. I would think that the glycerine, mixed as it was with the water, is there protecting the little yeast cells and such. At least I hope so...

Can someone confirm either way for me?

Most of my vials doesn't mix evenly and I never had problems with waking yeast up.
I suppose there is enough glycerine between cells to protect them (you just can't see it).

My yeast always settle out in the frige before freezing. Not a problem.

BBL_Brewer said:

My yeast always settle out in the fridge before freezing. Not a problem.

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Good to know. Now I'm not worried about them being good when I go to use them. Thinking about getting a tiny cooler (saw them at Lowes) to keep them in the freezer. Might put an ice pack in there too. If nothing else, it will help prevent any warmer air exposure (however brief) when getting into the freezer...

BTW, these things were SOLID within a few hours of being put into the freezer. Basically, in the time between my posts (~7 hours) they went from liquid to SOLID. I'll take some pics of the vials either tonight or tomorrow and post them up.

Picture of the vials... Graded A, B and C from left to right.

I have now done three strains and 18 vials/jars. The one thing that gets me still though is not knowing how much I'm putting in there. I'm using the 15ml of had pack=40-50 billion cells. Is that what everyone else uses?

theveganbrewer said:

I have now done three strains and 18 vials/jars. The one thing that gets me still though is not knowing how much I'm putting in there. I'm using the 15ml of had pack=40-50 billion cells. Is that what everyone else uses?

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As long as you have a way to estimate a rough cell count that's all that really matters. That way you have a general idea of how to do your starter before you brew. It's not an exact science, but you can't really know for sure what you've got without plating or scoping.

Just updated my earlier post with a picture... How do those look to you guys?? 50ml vials were used (baby 2L bottle forms)...

Professional labels. I can't add anything of value, since I just started, but what are the grades for? Did you put the same amount of yeast in each, or are they did they just settle differently?

I used a small cooler for most of my vials and was surprised how slow the freeze was. The alcohol also slowed it down significantly, I think it was a 24 hour process to freeze, possible longer.

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.

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

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

Matthewjscott said:

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

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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.

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

BBL_Brewer said:

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

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

BTW, I am from Kokomo as well.

Cheers!

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

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.

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.

fc36 said:

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.

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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.