Home Brew Forums > Home Brewing Beer > Brew Science > Glycerin/water ratio for freezing yeast
Reply
 
Thread Tools
Old 09-12-2011, 07:07 AM   #21
WheeledGoat
DisMember
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
WheeledGoat's Avatar
Recipes 
 
Join Date: Sep 2008
Location: Chicago, IL
Posts: 171
Liked 3 Times on 3 Posts
Likes Given: 6

Default

sooooooo.... what's the verdict on that fermentation?


__________________
Primary: Imperial IPA, Biermuncher's OctoberFAST, Zombie Dust
Secondary: Caberlot (my first wine!)
Cold Crashing: Goat's Spare Tire
Kegged & On Tap: Bavarian Hefeweizen, 3-year aged Cider

Projects: The Ravens Keezer - Custom Gas System - 10gal MLT
WheeledGoat is offline
 
Reply With Quote
Old 09-12-2011, 09:04 AM   #22
emjay
HBT_SUPPORTER.png
Feedback Score: 1 reviews
Recipes 
 
Join Date: Jan 2011
Location: Toronto, Ontario
Posts: 12,712
Liked 1716 Times on 1604 Posts
Likes Given: 1

Default

Quote:
Originally Posted by MalFet

Makes sense for evenly distributed alleles (.5^10 is mighty small, after all), but I've still got to think that this has the tendency to eliminate relatively less frequent traits (.9^10 isn't quite so tiny). If we did this with people, we'd run out of redheads pretty quick.
Well, the idea is obviously that genetic diversity isn't even ideal with yeast. You're taking 10 colonies of (virtually) genetically identical yeast cells. The aim is to keep the yeast the same, with minimal change. So not only is the disappearance of redheads not a problem, but you don't want them pop up, and when they do, you WANT them to be stamped out. The point is, that with good practice, the traits you want should *never* be relatively infrequent within your sample.

You can't really compare yeast with people like that, because there's an enormous, key difference - genetic diversity is completely undesirable when you're trying to maintain a pure yeast culture.


emjay is offline
 
Reply With Quote
Old 09-12-2011, 10:51 AM   #23
MalFet
/bɪər nɜrd/
HBT_LIFETIMESUPPORTER.png
Feedback Score: 1 reviews
 
MalFet's Avatar
Recipes 
 
Join Date: May 2010
Location: NYC / Kathmandu
Posts: 8,464
Liked 1389 Times on 921 Posts
Likes Given: 666

Default

Quote:
Originally Posted by emjay View Post
Well, the idea is obviously that genetic diversity isn't even ideal with yeast. You're taking 10 colonies of (virtually) genetically identical yeast cells. The aim is to keep the yeast the same, with minimal change. So not only is the disappearance of redheads not a problem, but you don't want them pop up, and when they do, you WANT them to be stamped out. The point is, that with good practice, the traits you want should *never* be relatively infrequent within your sample.

You can't really compare yeast with people like that, because there's an enormous, key difference - genetic diversity is completely undesirable when you're trying to maintain a pure yeast culture.
That's never been my understanding, based on hearing yeast people talk. Certainly some key features, particularly flocculation, are desirable in distribution.
__________________
"Be excellent to each other." -Benjamin Franklin
MalFet is offline
 
Reply With Quote
Old 09-28-2011, 04:41 AM   #24
StMarcos
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2008
Location: Sebastopol, CA
Posts: 969
Liked 31 Times on 26 Posts
Likes Given: 1

Default

From what I've read on yeast culturing, there is no substitution to tasting some of a trial beer prior to pitching the main tank. There IS a limit to what can be done with with scoping and plating etc. This was very frustrating to me when I first started culturing. Not that I've ever noticed a problem (or done trial batches for that matter), but I was hoping for a set of rules, that if followed, would guarantee a perfect # of healthy cells that were always mostly the same yeast I bought from the lab....
StMarcos is offline
 
Reply With Quote
Old 12-14-2014, 04:58 AM   #25
torosidis
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jun 2014
Posts: 7
Likes Given: 3

Default

With 25% glycerine my vials froze solid.Is it ok?
torosidis is offline
 
Reply With Quote
Old 12-15-2014, 04:25 AM   #26
beer_expert
Feedback Score: 0 reviews
Recipes 
 
Join Date: Dec 2014
Posts: 23
Liked 2 Times on 2 Posts
Likes Given: 1

Default

Greater than 10% glycerin leads to plasmid instability. ( plasmid instability = mutations )
10 % glycerine solution = 29.12 F degrees freezing point.
You just need to slow yeast metabolism to just under freezing.
Common misconceptions are that the colder the better.
Cryogenic temperatures can be used for gene modification on cells. Working on cells require them to stay still.
Others may know better but this is my protocols of how to keep yeast cultures dormant until needed.

Beer_Expert
Good beer should be Good AND Cheap


beer_expert is offline
 
Reply With Quote
Reply


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Table of Freezing Points of Alcohol Solutions rayg Brew Science 22 02-25-2014 05:34 PM
Help me to understand chloride - sulfate ratio hexmonkey Brew Science 78 01-27-2011 12:26 AM
How does freezing yield a 41%abv beer??? Sarrsipius Brew Science 16 03-15-2010 10:01 PM
mash ratio for no-sparge JLem Brew Science 14 11-20-2009 07:11 PM
Freezing a Dogfish Head 120min IPA Beer_Pirate Brew Science 17 06-16-2009 07:38 PM


Forum Jump

Newest Threads

LATEST SPONSOR DEALS