Saf Instant Yeast is a high potency, fast acting yeast that can be added directly to your dry ingredients without it having to be put in a starter first. Saf Instant Yeast is more than twice as active as regular compressed yeast. You need less - and less storage space. Storage Life: There is a one year expiration date stamped on the package from the date of manufacture. We have learned that you can expect to get a 2 year storage life from the date of manufacture if you keep it in a refrigerator. If you keep it in the freezer you can get up to 3 years storage life.