Guide to Making a Frozen Yeast Bank - Page 9

FlyGuy · 02-10-2008, 05:04 PM

It depends on the yeast strain, but count on 6 months for sure. Many could last for o two or three years.

The only one I have had fail before one year was a hefe yeast (Wyeast 3068). Apparently, they are notoriously difficult to keep viable.

But a lot of it depends on your storage conditions, too. Make SURE you store your yeast inside a cooler with ice packs inside your freezer because your freezer temps will fluctuate, which is probably the hardest thing on the yeast.

Best of luck if you try it!

sirsloop · 02-15-2008, 07:24 PM

hmm... just got ahold of a flask and stirbar and made a stirplate. I ordered 24 of those 16ml vials, a couple droppers, and a few smaller pyrex beakers for working with the yeast. I have fresh WLP400 belgian and WLP775 english cider yeast vials I'm going to bank up probably next week. I'm also going to take a sample of my Pistoles I just kegged and generate a WLP575 Belgian Golden starter out of some beer. Ill pack away 6 vials of each which will leave me 6 empties for some other yeast. Maybe I'll grab a WLP001 sample from someone in our homebrew club and start using that instead of Nottinghams.

My coworkers are calling me the mad scientist now... flasks, stirbars, yeast cultures, glycerine...lol..

**wizardofza** · 02-27-2008, 02:04 PM

Just tried this over the weekend. I have four pint-size mason jars with 1086 in them and can't wait to try them out.

Thanks for the thread!

Philip1993 · 02-28-2008, 04:13 PM

Back around post 66 we were discussing is layering was a problem. Mine are stored vertically and totally layered. They are also frozen solid.

I just pitched a 5 month old Wyeast 1332 with no problems. I warmed in room temp water for 2 hours and pitched into a 500ml wort.

FlyGuy · 02-28-2008, 06:37 PM

That's good to hear -- thanks.

I've learned a bit more about this, and I don't think layering is such a big deal anymore. If the yeast are 'acclimatized' in the fridge for 48 hours before freezing, and the glycerine solution is kept well mixed during that time, then they will become should become plenty cold-hardy.

biggenius29 · 02-29-2008, 03:06 AM

One question I have, when you make the glycerine solution, are you adding water and glycerine, or just glycerine and a little bit of beer from the starter?

FlyGuy · 02-29-2008, 04:16 AM

Quote:

Originally Posted by biggenius29

One question I have, when you make the glycerine solution, are you adding water and glycerine, or just glycerine and a little bit of beer from the starter?

I try NOT to add beer if possible. I crash cool my starters so that all the yeast drops to the bottom of my flask, and then I pipette off the bottom in the thickest part of the yeast 'sludge'. If some beer makes it in there, so be it. But now I shoot for about 15-20% glycerine, 30-35% water (both sterilized in the pressure cooker), and about 50% yeast slurry.

Philip1993 · 02-29-2008, 02:18 PM

I've been pitching the whole starter and then harvesting from the carbuoy post fermentation. After harvesting, the yeast is washed and I mix 20% glycerin with 80% wash slurry. In effect, I'm mixing 20% glycerin with about 65/15 distilled water & yeast.

ftlstrings · 03-05-2008, 04:47 AM

Thanks! This really helps to simplify the process for me! Now to convince my wife to let me take MORE freezer space.....

~M~

biggenius29 · 03-06-2008, 11:41 AM

When you put the vials in the pressure cooker, I see you leave the caps on the vials. When everything cools will they implode on themselves or are they able to withstand the vacume?