Jade asked whether storing yeast in the refrigerator reduces its potency.
In my experience, it does not -- I buy yeast in one pound packages and store
the whole package in the fridge. It takes me several months to use it up,
and I see no difference between the first loaf and the last.
I have had a bad experience, however, with freezing yeast. Lots of people
do it, and KA recommends it, but the batch I froze died. For the record, KA
replaced it for free.
So for me, there is always a Ziploc bag of yeast in the fridge -- and one of
the brown Fleischman's jars, which is easier to use, and refilled from the
bag.
Barbara