This stuff lasts for days in the fridge and months in the freezer, so make lots! Especially if you've just picked up a fresh blueberry haul and you're wondering what to do with all of them. Make batches of blueberry sauce and freeze it for later! Keep it in a glass jar or airtight container in the refrigerator for 3-5 days in the fridge or up to 3 months in the freezer! Closer to 6 months if it's in a deep freezer.