I buy yeast in bulk, as you do, and have bought the Red Star you mentioned. I
keep mine in the freezer, in it's original packing that is in a freezer
ziploc. I have kept it there for a year with no change in results. I take it
out, measure it, and make my bread. I don't bake weekly so this helps me save
the $$ that I want to over the three strip packs of yeast. It has worked for
years like this for me. I even have just finished a package that I've had for
over a year and it worked until I used it up. Really, I just have it handy in
my freezer that is part of my refrig in the kitchen.