Saf Instant Yeast is one of the top selling yeasts in the world. Fast acting and long lasting. Store in an airtight container; for 6 months at room temperature or in the fridge; or for a year or longer in your freezer. Comes in a large, 16-ounce (1 Pound) vacuum-packed bag. Safe Instant Yeast is one of the top selling yeasts in the world.