Store at room temperature in a large storage bag or airtight container for up to 4 days. I like to add a layer of paper towels on the bottom and over the top to absorb excess moisture. Another way to prevent muffins from getting soggy is to put a saltine cracker in the same container! To reheat, microwave one or two at a time for 20 to 30 seconds, or until warm. If they are frozen, I recommend thawing them first.