Prepare or have ready:
- 4 medium beets (about 1 ½ pounds), cooked, peeled, and sliced
Place the beets in a clean quart jar. Combine in a medium saucepan and bring to a boil:
- 1 cup cider vinegar
- 1 cup beet cooking liquid or water
- 1 small onion, thinly sliced
- ¼ cup sugar
- 10 black peppercorns
- 6 whole cloves
- 2 bay leaves
- 1 teaspoon salt
- (1 teaspoon prepared horseradish)
Pour over the beets. Let cool, cover, and refrigerate for at least 12 hours before serving. Store refrigerated for up to 1 month.