Of course! Though I usually do not prefer frozen food, but due to lack of time or unavailability of ingredients you can make it ahead of time. Seal in an airtight container or freezer bag, removing as much air as possible. Creamed spinach will last for up to 2 months in the freezer. If you are planning to use your creamed spinach within a few days, you can also easily refrigerate it for up 1 to 2 days.