Yes, you can definitely make the beets ahead of time. Roasted beets keep nicely in an airtight container in the fridge for up to 5 days. And if you'd like to freeze leftover beets, wrap them tightly in plastic wrap or foil and store them in an airtight container in the freezer for up to three months. Thaw them in the refrigerator before using. If you're a big beet fan and looking for other ways to use them, you'll love (and maybe even obsess over) my balsamic-glazed roasted beets.