Brewing Master

Question:

I am about to gear up and try the yeast freezing experiment again.  I wondered if anyone had any experience/success with it. A friend said that glycerol at 17% solutions worked, and he froze at -50 F I consulted my Mark’s handbook and it says a 47% by volume solution would prevent freezing to -10F. I also read you can freeze them at -80 F in a 15% glycerol solution http://bioinformatics.duke.edu/yeast/Info%20and%20Protocols/Freezing_… tm I have no way to keep them less than -10 to -15 F.  So any help is appreciated. Cheers, Mike

Response:

Mike Not sure exactly what you’re doing, but I have a simple method I use to keep yeast slurry for re-pitching a couple of months down the track. It’s OK for the yeast mixture to actually freeze, so you don’t need quite as much glycerol as is required to prevent freezing of the water.  The mechanism of protection (as much as I understand it) is that the glycerol cushions the lipid walls and prevents local freezing of the cell.  So the final frozen mixture has a "frozen smoothie" texture. My freezer gets down to about -4F, which is about the standard these days for keeping food.  It won’t give you the sort of "forever" storage that microbiologists like to use, but it’s OK for at least 3 months, maybe more. About 10% by volume glycerol keeps my yeast viable at this temperature.  Go to higher levels if you want. Chris – Hide quoted text — Show quoted text – I am about to gear up and try the yeast freezing experiment again.  I wondered if anyone had any experience/success with it. A friend said that glycerol at 17% solutions worked, and he froze at -50 F I consulted my Mark’s handbook and it says a 47% by volume solution would prevent freezing to -10F. I also read you can freeze them at -80 F in a 15% glycerol solution http://bioinformatics.duke.edu/yeast/Info%20and%20Protocols/Freezing_… tm I have no way to keep them less than -10 to -15 F.  So any help is appreciated. Cheers, Mike

Response:

I have an old (1980) brewing book "Beer Kits and Brewing" by Dave Line where Dave suggests adding 1 tablet of saccharin per gallon of wort prior to bottling to "smooth out the roughness without imparting a detectable sweetness." I’ve never tried this, mostly because I can’t buy saccharin, it’s not sold in Canada. My questions are: 1. Has anyone tried this, and if so what is your experience? 2. Would aspartame (legal in Canada) work as well? Thanks in advance. Robert

Response:

I’ve had a lot of success freezing using 10-15% glycerol.  I use a deep freeze (-20C, no idea what that is in Fahrenheit), and the samples stay good for years.  Glycerol prevents the formation of ice crystals which normally would lacerate the walls of the yeast.  I work in a lab and we frequently freeze bacterial samples at -80 or colder (liquid nitrogen) using 15%.  Anymore then 15% will start having toxic effects that may affect the viability of the cells. Hope this helps Bryan – Hide quoted text — Show quoted text – I am about to gear up and try the yeast freezing experiment again.  I wondered if anyone had any experience/success with it. A friend said that glycerol at 17% solutions worked, and he froze at -50 F I consulted my Mark’s handbook and it says a 47% by volume solution would prevent freezing to -10F. I also read you can freeze them at -80 F in a 15% glycerol solution http://bioinformatics.duke.edu/yeast/Info%20and%20Protocols/Freezing_… tm I have no way to keep them less than -10 to -15 F.  So any help is appreciated. Cheers, Mike

Response:

Where would a normal human being find glycerol? —  Dan Listermann Check out our E-tail site at http://www.listermann.com Take a look at the anti-telemarketer forum.  It is my new hobby!

– Hide quoted text — Show quoted text – I’ve had a lot of success freezing using 10-15% glycerol.  I use a deep freeze (-20C, no idea what that is in Fahrenheit), and the samples stay good for years.  Glycerol prevents the formation of ice crystals which normally would lacerate the walls of the yeast.  I work in a lab and we frequently freeze bacterial samples at -80 or colder (liquid nitrogen) using 15%.  Anymore then 15% will start having toxic effects that may affect the viability of the cells. Hope this helps Bryan I am about to gear up and try the yeast freezing experiment again.  I wondered if anyone had any experience/success with it. A friend said that glycerol at 17% solutions worked, and he froze at -50 F I consulted my Mark’s handbook and it says a 47% by volume solution would prevent freezing to -10F. I also read you can freeze them at -80 F in a 15% glycerol solution

http://bioinformatics.duke.edu/yeast/Info%20and%20Protocols/Freezing_… – Hide quoted text — Show quoted text – tm I have no way to keep them less than -10 to -15 F.  So any help is appreciated. Cheers, Mike

Response:

I’ve had a lot of success freezing using 10-15% glycerol.  I use a deep freeze (-20C, no idea what that is in Fahrenheit), and the samples stay good for years.  Glycerol prevents the formation of ice crystals which normally would lacerate the walls of the yeast.  I work in a lab and we frequently freeze bacterial samples at -80 or colder (liquid nitrogen) using 15%.  Anymore then 15% will start having toxic effects that may affect the viability of the cells. Hope this helps Bryan

        I work in a fission yeast lab and we use 30% glycerol solutions for freezing at -80C.  I do they same for my brewing yeast with good results.  The problem with freezing at home is some people have freezers with defrost cycles.  That won’t be good for the yeast. Warren Place

Response:

15% glycerin in water should be about right. Do a search on "yeast glycerin freeze" and you’ll get lots of hits. – Hide quoted text — Show quoted text – Cool!  What was the solution for freezing yeast? I was pretty sure, but I looked it up: http://www.jtbaker.com/msds/g4774.htm They’re the same thing. Fred Stone The wine conditioner we sell is Brew King’s.  It is sucrose and sorbic acid. We have something called "Finishing Formula" which is glycerin, but no glycerol. Drug store. Some winemaking shops call it "wine conditioner". Where would a normal human being find glycerol? —  Dan Listermann

– Fred Stone aa # 1369 BAAWA Brewmaster

Response:

A guy here in Sweden has been experimenting with freezing yeast in sugar solution. And very successfully so, apparently…

Yeast can also be stored for long periods in plain distilled water (and at room temperature.)  IIRC from a thread on the UK homebrewing list a couple of years ago – fill a small vial, test tube etc. with distilled water, sterilize in pressure cooker, cool, transfer a small amount of yeast, cap and you’re done.  It’s important not to put too much yeast in, only enough to cause a slight haze to the water.  This is really an alternative to slants.  Of course you need to step it up a few times once you’re ready to brew. Geoff

Response:

I have an old (1980) brewing book "Beer Kits and Brewing" by Dave Line where Dave suggests adding 1 tablet of saccharin per gallon of wort prior to bottling to "smooth out the roughness without imparting a detectable sweetness." I’ve never tried this, mostly because I can’t buy saccharin, it’s not sold in Canada. My questions are: 1. Has anyone tried this, and if so what is your experience? 2. Would aspartame (legal in Canada) work as well? Robert

        Tried sucralose in a sweet stout once.  Worked very well.  I recommend it over aspartame because its sweetness doesn’t fade with time. www.sucralose.com is where I got it but they may sell it in a store near you. Warren Place

Response:

Cool!  What was the solution for freezing yeast? —  Dan Listermann Check out our E-tail site at http://www.listermann.com Take a look at the anti-telemarketer forum.  It is my new hobby!

– Hide quoted text — Show quoted text – I was pretty sure, but I looked it up: http://www.jtbaker.com/msds/g4774.htm They’re the same thing. Fred Stone The wine conditioner we sell is Brew King’s.  It is sucrose and sorbic acid. We have something called "Finishing Formula" which is glycerin, but no glycerol. Drug store. Some winemaking shops call it "wine conditioner". Where would a normal human being find glycerol? —  Dan Listermann

Response:

Most drug stores sell glycerol, over the counter.  I’d recommend buying a small bottle (no more then 100 ml), as you don’t need much, and it can go bad.  A wort/glycerol solution can be sterilized by boiling without affecting the glycerol.  Here’s what I usually do: 1) Fill a 15 ml test tube 2/3rds full with a heavily hopped wort, SG ~ 1.045. Add a loop (or drop) of your yeast (best to take this right from the smack pack or starter).  Plug the tube with a sterile cotton ball, or cap.  Let ferment 1 day, the place in the fridge for a second day. 2) Use a sterilized eye dropper or pipette to draw off the fluid, but leave the yeast pellet behind.  Resuspend the yeast cells in a small volume (1 ml) of heavily hopped wort (S.G. 1.025) supplemented with 15% glycerol.  Immediately transfer to a deep freeze.  If you have them 1.5 ml eppindorf tubes are great for this. 3) To use the yeast thaw in a fridge, resuspend the any pellet that may have formed, then add to a 100 ml volume of heavily hopped wort (1.030-1.045).  Once this has reached krausen (sp?) you can pitch it into a larger sized starter, and use as usual.  If you are going to reculture the yeast take a sample from the starter and freeze as in 1&2. Hope this helps Bryan Heit – Hide quoted text — Show quoted text – Where would a normal human being find glycerol? —  Dan Listermann Check out our E-tail site at http://www.listermann.com

Response:

Where would a normal human being find glycerol? —  Dan Listermann

I did some research on this last summer… I was concerned about toxicity and just what the heck, if anything, glycerol would do to my beer (or me). As it turns out the stuff is pretty much non-toxic though you wouldn’t want to drink it straight. Although I never bothered to look, supposedly it can be found at your local pharmacy. Look near skin care products and such…. Hope this helps, Cheers, Matt Jarvis Eugene, Oregon USA The BrewDomain www.BrewDomain.com

Response:

Hi Mike A guy here in Sweden has been experimenting with freezing yeast in sugar solution. And very successfully so, apparently. Here’s what he did: 1 volume of sugar with 2 volumes water was boiled a couple of minutes and then cooled After this a thick yeast slurry from a previous batch was added (from a bottle where the yeast had been allowed to settle hard). The volume of yeast slurry was the same as the volume of the sugar-water solution. This mixture was put in the freezer for eight months, then it was revived by letting it thaw in room temperature for about 3 hours. It was then added to a starter (about a liter).  Activity after one hour. He brewed his regular pilsner with the revived yeast and the fermentation and the taste was exactly as usual. I’m going to try this myself next time I want to save a yeast. /peter

yeast freezing experiment again.

Response:

I was pretty sure, but I looked it up: http://www.jtbaker.com/msds/g4774.htm They’re the same thing. Fred Stone – Hide quoted text — Show quoted text – The wine conditioner we sell is Brew King’s.  It is sucrose and sorbic acid. We have something called "Finishing Formula" which is glycerin, but no glycerol. Drug store. Some winemaking shops call it "wine conditioner". Where would a normal human being find glycerol? —  Dan Listermann

Response:

The wine conditioner we sell is Brew King’s.  It is sucrose and sorbic acid. We have something called "Finishing Formula" which is glycerin, but no glycerol. —  Dan Listermann Check out our E-tail site at http://www.listermann.com Take a look at the anti-telemarketer forum.  It is my new hobby!

– Hide quoted text — Show quoted text – Drug store. Some winemaking shops call it "wine conditioner". Where would a normal human being find glycerol? —  Dan Listermann

Response:

Drug store. Some winemaking shops call it "wine conditioner". – Hide quoted text — Show quoted text – Where would a normal human being find glycerol? —  Dan Listermann

Response: