Store Brown Butter Pumpkin Bread in an airtight container at room temperature for up to 2 days or refrigerate it for 5 days. For longer storage, wrap individual slices tightly in plastic wrap and place them in a freezer-safe bag for up to 3 months. To reheat, warm a slice at 300°F for 6 to 8 minutes or microwave it for 8 to 12 seconds. Stop if the icing starts melting. Discard the loaf if you notice mold, a fermented smell or unusually sticky moisture on the crumb.