I would say go a little longer maybe 20-30 minutes to be on the safe side. Botulinum can actually survive the boiling water method, but since wort could be considered an acidic medium (pH 5.2) with careful sanitation you should be ok. Also don't start your boil time until after the pot returns to a full boil once you place your jars into the water bath.
Do you know how to make a yeast starter? Then why not farm yeast and freeze it?
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I would say go a little longer maybe 20-30 minutes to be on the safe side. Botulinum can actually survive the boiling water method, but since wort could be considered an acidic medium (pH 5.2) with careful sanitation you should be ok. Also don't start your boil time until after the pot returns to a full boil once you place your jars into the water bath.
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BBL_Brewer
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I've also soaked some in star san for a couple hours when I was short on sterile containers.
theveganbrewer
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I had no choice to boil some of those plastic 50ml vials from amazon and was surprised they held up. I had some a while back from a different manufacturer that turned cloudy, these remained clear and didn't warp.
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IT'S WORKING.....IT'S WORKING!!!! Been frozen for a month and put it on the stir plate last night. 24 hours later...we have fermentation!
Here were my steps:
Day 1...
1) I washed the yeast well, and stored in fridge overnight.
2) Boiled a solution of 30% glycerin/70% water in a sanitized jar in microwave for 2 minutes. Then store in fridge overnight as well.
3) Boiled my 1 oz. storage vials for 20 minutes. Removed and cooled them, then let soak in star-san overnight.
Day 2...
1) Filled a sanitized measuring glass with equal amounts of yeast and glycerin solution.
2) Mixed them well, then used a sanitized syringe to fill my vials about 80% full. Then put the cap on tightly.
3) Stored in fridge for 2 days. Whenever I would go to fridge, I would shake the vials to get yeast back into suspension.
Day 4...
1) Loosened caps and stored in deep freezer.
Day 5...Tightened caps up as yeast was frozen.
Week 4...
1) Removed from freezer and put in a 2 quart jar of 70* water until thawed. Then added to stir plate and starter.
Thank you so much for this post!:rockin: This information is going to save me a ton of money!
Here were my steps:
Day 1...
1) I washed the yeast well, and stored in fridge overnight.
2) Boiled a solution of 30% glycerin/70% water in a sanitized jar in microwave for 2 minutes. Then store in fridge overnight as well.
3) Boiled my 1 oz. storage vials for 20 minutes. Removed and cooled them, then let soak in star-san overnight.
Day 2...
1) Filled a sanitized measuring glass with equal amounts of yeast and glycerin solution.
2) Mixed them well, then used a sanitized syringe to fill my vials about 80% full. Then put the cap on tightly.
3) Stored in fridge for 2 days. Whenever I would go to fridge, I would shake the vials to get yeast back into suspension.
Day 4...
1) Loosened caps and stored in deep freezer.
Day 5...Tightened caps up as yeast was frozen.
Week 4...
1) Removed from freezer and put in a 2 quart jar of 70* water until thawed. Then added to stir plate and starter.
Thank you so much for this post!:rockin: This information is going to save me a ton of money!
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BBL_Brewer
Well-Known Member
I'm glad it worked out for ya. And yes you will save a lot of money.
Brewzologist
Active Member
FYI... See this link to post #714 on successfully using frozen yeast after 15 months stored in a frost-free fridge...
https://www.homebrewtalk.com/f13/guide-making-frozen-yeast-bank-35891/index72.html#post5422216
https://www.homebrewtalk.com/f13/guide-making-frozen-yeast-bank-35891/index72.html#post5422216
![Craft A Brew - Safale BE-256 Yeast - Fermentis - Belgian Ale Dry Yeast - For Belgian & Strong Ales - Ingredients for Home Brewing - Beer Making Supplies - [3 Pack]](https://m.media-amazon.com/images/I/51bcKEwQmWL._SL500_.jpg)
Yep, should be able to store yeast for a long time if the conditions are good. The colder the better but obviously just freezer temps work fine.
CloverBrew
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Sorry for pulling up an old post, but I was curious about the "boiling the 50 ml Amazon vials" thing. If you get the product like these that are listed as sterile in the product description, there's no reason to boil them, right? Just pop open, fill, and re-seal, ya?
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Correct!
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Simple question I can't seem to find answered in this thread: Are folks autoclaving the vessel they make the yeast starter in? Or just the equipment they use to handle/store the yeast when harvesting from the starter?
If you have an autoclave available you can just make your starter from wort made from malt extract and then autoclave and everything is sterile. If you don't, you can sanitize your flask or growing vessel and then use whatever wort you are using for your starter (presumably boiled). Everything should be carefully sanitized or sterilized for starters because it has the most danger of getting contaminated. If it does and you freeze that yeast, the subsequent brews will all have that contamination. Better safe than sorry.
I do have an autoclave (more precisely, a pressure canner). I currently autoclave starter wort, and my plan would be to also prepare some autoclaved jars of glycerin/water solution. I'm also going to get a stainless baster (which I really should have for hydrometer samples anyway), and just wrap that in foil and stick in the oven for about a half hour prior to starting the harvesting.
But autoclaving the flask at the outset of building up the yeast culture would be a whole 'nother step, and rather a pain in the ass, that I'm hoping to avoid. What is the general consensus on that, is that step essential?
But autoclaving the flask at the outset of building up the yeast culture would be a whole 'nother step, and rather a pain in the ass, that I'm hoping to avoid. What is the general consensus on that, is that step essential?
PasbitinusBluinusRibbinus
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Edit: Nevermind! Answered my own questions.
Folks:
I don't autoclave anything. Used only Basic-A or 1-Step soln. for several hundred vessels and containers and had NO infections. My oldest is an ale, from 10/12. I do, however, always wear rubber gloves.
The warning on ethylene glycol is a very good idea, but you can be totally safe by decanting all the liquid after each time you step up the yeast mass; just pour it off.
I don't autoclave anything. Used only Basic-A or 1-Step soln. for several hundred vessels and containers and had NO infections. My oldest is an ale, from 10/12. I do, however, always wear rubber gloves.
The warning on ethylene glycol is a very good idea, but you can be totally safe by decanting all the liquid after each time you step up the yeast mass; just pour it off.
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BBL_Brewer
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If you're careful, you can get by with the minimum. But an ounce of prevention is worth a pound of cure.
climateboy
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I don't know if others have tried this, but to save a step and to get the purest culture possible, I've been pouring a small portion of the slurry from the Wyeast pack or White Labs vial or ECY jar directly into my sterilized, glycerin/water-filled test tubes. Then I go on to use the reduced initial volume to make my starter. Anyone see a drawback to this approach?
I'm planning on using this method, and I have a pressure canner, but I still don't see why you wouldn't can the water doing hot water bath canning? It's not like the ph of water is low enough to require pressure canning and when using such small jars, it would actually take less time in the hot water bath. You could have done a few batches of canned water in the time it would take to pressure can and cool one batch.
Did I misread? Are you canning wort and using that for a starter?
Edit: Nevermind.. I'm thinking backwards.. You'd need a ph of 4.6 or less to hot water can.
Did I misread? Are you canning wort and using that for a starter?
Edit: Nevermind.. I'm thinking backwards.. You'd need a ph of 4.6 or less to hot water can.
Nothing other than you'd have to make a small starter, say 500ml to start off such a small number of cells. Then go to 1L or 2L or whatever to get your numbers.
If you have the ability to step up to 5L on the first go, you can save either 100 billion cells per jar, knowing you'd need to make one starter most times when you thaw it, or you could do more and make it pitch able.
I'm about to do this with some San Fran lager yeast and had planned on packaging it in approx. 300-400 billion cell increments. This way, I can warm it and pitch, at least at the gravities I would be using that yeast at. I have ECY21 Kolsch I'm going to do next, and will package that between 100-200 billion cells.
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BBL_Brewer
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I'm stating the obvious, but you'd want to get the freshest pack possible so you're freezing healthy yeast and keeping your viable cell count up. And like cerevid pointed out, you'll have to start with small steps which will increase the amount of time it will take you to hit your pitching rate. It would help decrease chances of contamination though if you're not confident about your sanitation.
So long as you're very careful to sanitize the package and work under an alcohol lamp in a draft free area, I think that's a great idea. Realistically if it's just a couple vials you're using I don't think you need to reduce your starter size. 10x step ups is what the big boys do, so if you'd do a 2Q starter with 100B cells, doing it with 75B cells is still doable. Your final count won't be quite as high as it would have been, but the yeast will reproduce plenty to make you a pitchable starter.
SamBrewer
Well-Known Member
I always start from a wyest packs!
I usually make 6 vials of yeast (17ml of slurry without breaking the inner bag) + 1,5ml glycerine from each packege. So every year I just buy the strain of yeasts that I want to use and freeze them to be able to use it all year long.
I made some calculation and also perform a lot of test/brewing with this method, you need to start with a very small starter (200-300ml) and then grow up to 1,6 liter. I've tried also a 3 starter procedure when I need lot of yeast. No contamination, or any other kind of problem found.
So, I've recently discovered this thread. I, too, have had an interest in freezing yeast and am assembling the gear to do it. But the knowledge... that's been a little trickier. This thread has been a gold mine of data for me and I'd like to throw in something I came across as it seems relevant.
When I suspect that a good deal is known about something pretty technical but nobody technical is talking, I turn to patent searches. They can refuse to give *you* any info, but if it's a coveted process it gets spelled out in a patent. So, I came across this patent:
1) Granted in 1997. It deals with baker's yeast and the cryoprotectant properties of adding glycerol in various concentrations and freezing at -21 deg C. Concentrations were .2 M, .3 M, and .4 M. The .4 M concentration had the greatest improvement of yeast viability .4 M translates to just 3.7% glycerol in water concentration by weight (2.8% by volume), an interesting level of concentration given Forkhead's experiment indicating that, at this freezing temp, he found 7.5% by volume concentration ideal. I think this brackets the range we're looking at: 3% to 8%. Pretty small doses.
2) This excerpt shows glycerol uptake by yeast over a period of days. Interesting, huh? Remember, though, glycerol is yeast poison, so these extended contact times, while increasing glycerol uptake, don't translate necessarily to better viability. There must a sweet spot.
3) Finally, this excerpt shows proof times after freezing then thawing and proofing the yeast. Using the proof times of baker's yeast is a clever way of assessing yeast viability without high tech equipment, I think. Bottom line: 3 days at 4 deg C is optimum data point for yeast viability. Based on this, I would recommend that the 4 deg C storage time be increased from 48 hours to 72 hours.
A lovely creation this thread and it's associated tutorial is.
Thanks to all.
View attachment 1patent for glycerol-water yeast treatment.pdf
View attachment 2uptake of glycerol.pdf
View attachment 3yeast performance.pdf
When I suspect that a good deal is known about something pretty technical but nobody technical is talking, I turn to patent searches. They can refuse to give *you* any info, but if it's a coveted process it gets spelled out in a patent. So, I came across this patent:
1) Granted in 1997. It deals with baker's yeast and the cryoprotectant properties of adding glycerol in various concentrations and freezing at -21 deg C. Concentrations were .2 M, .3 M, and .4 M. The .4 M concentration had the greatest improvement of yeast viability .4 M translates to just 3.7% glycerol in water concentration by weight (2.8% by volume), an interesting level of concentration given Forkhead's experiment indicating that, at this freezing temp, he found 7.5% by volume concentration ideal. I think this brackets the range we're looking at: 3% to 8%. Pretty small doses.
2) This excerpt shows glycerol uptake by yeast over a period of days. Interesting, huh? Remember, though, glycerol is yeast poison, so these extended contact times, while increasing glycerol uptake, don't translate necessarily to better viability. There must a sweet spot.
3) Finally, this excerpt shows proof times after freezing then thawing and proofing the yeast. Using the proof times of baker's yeast is a clever way of assessing yeast viability without high tech equipment, I think. Bottom line: 3 days at 4 deg C is optimum data point for yeast viability. Based on this, I would recommend that the 4 deg C storage time be increased from 48 hours to 72 hours.
A lovely creation this thread and it's associated tutorial is.
Thanks to all.
View attachment 1patent for glycerol-water yeast treatment.pdf
View attachment 2uptake of glycerol.pdf
View attachment 3yeast performance.pdf
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BBL_Brewer
Well-Known Member
Very cool. Never thought about checking for patents. Very sneaky, I like it. Thanks for the contribution!
Having read through all of the posts on this thread, I now see that Forkhead's ideal glycerol%concentration was amended from 7.5% to 15% for the long term viability experiment. The 7.5% number came from a short term test where the sample was frozen and then a short time later, thawed. Since the point of freezing is long term viability, he amended to 15%.
It is curious that the ideal glycerol%concentration for freezing hovers around 15% whether freezing at -20C or -80C. An inpection of a glycerol%solution (by weight) table indicates that a 15% glycerol solution (by weight) yields a specific gravity of about 1.036. Curiously, this is an ideal gravity of a yeast starter when propagating yeast. Could it be that the 15% glycerol solution is ideal because of an ideal osmotic pressure gradient? Not too much. Not too little. But just the right amount of inward osmotic pressure for optimum glycerol uptake and yeast comfort?
It is curious that the ideal glycerol%concentration for freezing hovers around 15% whether freezing at -20C or -80C. An inpection of a glycerol%solution (by weight) table indicates that a 15% glycerol solution (by weight) yields a specific gravity of about 1.036. Curiously, this is an ideal gravity of a yeast starter when propagating yeast. Could it be that the 15% glycerol solution is ideal because of an ideal osmotic pressure gradient? Not too much. Not too little. But just the right amount of inward osmotic pressure for optimum glycerol uptake and yeast comfort?
Hey all,
Regarding the glycerin/water solution, is there reason to believe that this stuff would have a limited shelf life (uncanned, in the fridge)?
Basically, in preparation for harvesting yeast to freeze, I can up some 4 oz jars of 2-1 glycerin/water mixture. I then blend in the solution 4-1 in the yeast slurry which gives me around 17% glycerin. Probably close enough for government work...
Anyhow, when I'm done, I have leftover solution (by design, so as to make sure I have enough!). What I would like to do is screw the top back on the jar and stick it in the fridge, then next time I pull out the pressure canner to make starter wort or whatever, re-combine the mostly-empty jars and re-can it to sterilize it.
The stuff could potentially be sitting in the refrigerator for a couple of months.
Is there anything that would likely go wrong with it? Obviously any organisms that were in it would get killed in the canner, but is there nasty stuff that it could have grown, or is the solution too dense?
Thanks
Regarding the glycerin/water solution, is there reason to believe that this stuff would have a limited shelf life (uncanned, in the fridge)?
Basically, in preparation for harvesting yeast to freeze, I can up some 4 oz jars of 2-1 glycerin/water mixture. I then blend in the solution 4-1 in the yeast slurry which gives me around 17% glycerin. Probably close enough for government work...
Anyhow, when I'm done, I have leftover solution (by design, so as to make sure I have enough!). What I would like to do is screw the top back on the jar and stick it in the fridge, then next time I pull out the pressure canner to make starter wort or whatever, re-combine the mostly-empty jars and re-can it to sterilize it.
The stuff could potentially be sitting in the refrigerator for a couple of months.
Is there anything that would likely go wrong with it? Obviously any organisms that were in it would get killed in the canner, but is there nasty stuff that it could have grown, or is the solution too dense?
Thanks
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