I recently opened a package of SAF yeast that had been languishing in my sister's chest freezer; it had an expiration date of 2005. After successfully proofing a teaspoon, I tried it in one of my usual bread machine recipes and it worked just fine. I certainly wouldn't recommend planning to keep yeast around that long, but it's good to know it can last. The upshot: don't be afraid to buy the one pound package, keep it in the freezer, and proof it first if it's been a while since you last used it.

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