I've been using yeast purchased in bulk (2 lb vacuum-packed bags) for over
two decades and almost never have any go bad. Here's how I store and use
it: I keep three (3) jars in my refrigerator, one is a wide-mouth quart
mason jar (any quart jar with a tight-fitting, gasketed lid will do) a
12-oz mason jar and one of those little four ounce brown jars that yeast
can be purchased in in the store. (probably the small jar and one big one
will do, but I find a 2 lb bag of yeast won't fit into just the quart jar
and the 4 oz jar). Keep all yeast in these jars, tightly sealed and in the
refrigerator at all times. Whenever using yeast always take it from the
smallest jar, never the big ones. Open the small jar only for the few
seconds required to get the yeast out then immediately close it (tightly)
and return to the refrigerator. Open the 12 oz jar only when the 4 oz jar
is empty, refill the 4 oz jar and tightly seal both immediately and
refrigerate. Open the quart jar only when both smaller jars are empty.
Again, don't leave 'em unsealed or un-refrigerated any longer than necessary.
Doing this means the yeast in the quart jar is only exposed to air two or
three times before it finally finds its way into the 4 oz jar, from which
you work when baking.
I purchased one of these bags for a neighbor, an occasional baker, a few
years ago and suggested she do some similar procedure with it. I learned
some months later that she hadn't done it, that the yeast had died from
being opened and exposed to air too many times. So, I take it that my
procedure works.
You can certianly freeze it if you wish, but by limiting the exposure to
warm air I've demonstrated that it isn't strictly necessary.
Fred
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---- Fred Smith -- fredex@fcshome.stoneham.ma.us ----------------------------