I recently purchased a lb package of instant yeast. The contents can last for months before they are depleted. Will freezing the yeast effect its performance when used in time?
The effects of freezing instant yeast are, in my opinion, negligible. I have had SAF instant yeast sealed in a ziplock bag in the freezer for at least a year and it seems to work as well as the day it arrived at my doorstep.
I buy my yeast in bulk from Sam's club and it goes directly into my freezer when I get it home. I recently found a package of yeast that somehow got pushed back to the back of the freezer and overlooked for two years past it's expiration date. I opened it yesterday and made my usually sandwich bread and it was just fine. I couldn't tell that there was any difference in the yeast at all.
I think freezing yeast keeps it good for much longer.
I make sourdough, my husband is the only one who uses instant yeast at home. He usually keeps 1/2 a bag in the fridge and the other 1/2 in the freezer. Didn't seem to make any difference in his breads. Al
I also buy mine in bulk and freeze them sometimes for over a year. No effect on yeast's effectiveness that I noticed.
George (Author of What Recipes Don't Tell You)
This, according to yeast company techs I've met from SAF, Red Star, and Lesaffre:
Freezing will kill some of your yeast. How much can depend upon the type of yeast (fresh (compressed) yeast survives better than dry) and how quickly your product freezes. Blast freezing kills fewer of them, perhaps because fewer ice crystals have enough time to form inside the yeast cells. A long, slow freeze of bread dough (or a package of yeast) in your freezer would tend to extend the danger, apparently.
Most printed bread recipes have more than the necessary amount of yeast for leavening bread dough anyway. So if some percentage of the yeast is killed by freezing, you may not notice for quite a while.
Dough that's meant to be frozen and subsequently thawed before proofing and baking often has twice the normal amount of yeast for a dough that isn't meant to be frozen. That acts as pretty good insurance.
For a very rich dough (12% or more sugar, maybe 15% or more fat), tripling the yeast for a dough to be frozen raw is not uncommon.
Of course, variables like handling, holding temperature, and the health of the yeast before freezing matter quite a bit, so mileage can vary.
SAF yeast will keep fine in the fridge or freezer. You can just take it out as you need it.
I use instant dried yeast and on our purchased container it recommends you either freeze or keep in the fridge to extend the life of the yeast.
When I use it straight from the freezer I place it in a small amount of warm water and a half Tspoon of brown sugar for 10 minutes or till it is nice and frothy.
I have not had a bad experience as yet..............Peter