Home Brew Forums > Home Brewing Beer > Fermentation & Yeast > Viability of Frozen Yeast
Reply
 
Thread Tools
Old 11-09-2013, 07:28 PM   #1
mattrennert
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2009
Location: Madison, WI
Posts: 62
Liked 2 Times on 2 Posts
Likes Given: 1

Default Viability of Frozen Yeast

Anyone have a rule of thumb for viability of frozen yeast? I have heard 5% drop per week for active yeast, I would imagine freezing slows the degradation..

Maybe 2% loss per week is reasonable?


mattrennert is offline
 
Reply With Quote
Old 11-10-2013, 01:32 AM   #2
Calder
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2010
Location: Ohio
Posts: 6,550
Liked 391 Times on 349 Posts
Likes Given: 7

Default

Dry or liquid?

For liquid, freezing will kill the yeast. The ice crystals pierce the cell walls of the yeast. You would be lucky for any to survive unless you used a glycerin solution.

For dry - it will last for years. Dry looses about 4% per year at fridge temperatures, so would tale 10 years to be about 50% viability.


Calder is offline
 
Reply With Quote
Old 11-10-2013, 02:43 AM   #3
mattrennert
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2009
Location: Madison, WI
Posts: 62
Liked 2 Times on 2 Posts
Likes Given: 1

Default

To be more clear...
I'm wondering about viabilty of frozen yeast yeast slurry in a solution with 15% glycerine, stored in a non-frost free freezer.
mattrennert is offline
 
Reply With Quote
Old 11-10-2013, 02:48 AM   #4
kh54s10
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
kh54s10's Avatar
Recipes 
 
Join Date: Aug 2011
Location: Tiverton, Rhode Island
Posts: 7,842
Liked 827 Times on 697 Posts
Likes Given: 216

Default

I don't know about the degradation, but I make vials with 5 ml yeast, 5 ml glycerin and 10 ml water. I resurrected a vial that a couple weeks ago had been frozen since 11/11.

I start with a weak 250 ml starter then step it up a couple more times. The 11/11 one started fermentation within 6 hours.
kh54s10 is offline
 
Reply With Quote
Reply


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
frozen yeast viability ukeedogs Fermentation & Yeast 5 03-28-2013 12:51 PM
Yeast age vs viability chuckda4th Fermentation & Yeast 13 01-19-2013 01:48 PM
Old frozen yeast viability = good passedpawn Fermentation & Yeast 4 06-25-2010 05:07 AM
yeast viability mediumsk All Grain & Partial Mash Brewing 3 10-03-2007 09:38 PM
Yeast viability at age RedSun All Grain & Partial Mash Brewing 4 07-27-2007 12:50 AM


Forum Jump

Newest Threads

LATEST SPONSOR DEALS