Preheat the oven to 375.
Gather your ingredients. The market only had golden beets today which I prefer as they don't turn your hands red.
Trim the stems and leaves from the beets.
Wrap each beet in foil.
Bake beets until tender, about 1 hour.
Unwrap to cool and then slip off the skins.
In a small non-reactive saucepan, combine the vinegar, water, cumin seeds, sugar and salt. Bring to a simmer and stir until the sugar and salt dissolve about 4 minutes.
Cut the beets into 1/4 inch thick slices.
Put the beets in a glass or ceramic bowl.
Pour the hot marinade over the beets. Let cool.
Cover and refrigerate for at least 12 hours or up to 2 weeks. The beets will become increasingly sour as they stand.
Drain before serving. This recipe is from the cookbook, Olive Trees and Honey: A Treasury of Vegetarian Recipes from Jewish Communities Around the World by Gil Marks.