01 -
Scrub beets and trim greens and roots. Place in a pot, cover with water by 1 inch, bring to a boil, then simmer until fork-tender, 30 to 45 minutes. Drain and cool until safe to handle.
02 -
Rub off the skins with your fingers. Slice into 1/4-inch rounds or quarter wedges.
03 -
Combine vinegar, water, sugar, salt, mustard seeds, allspice, cloves, cinnamon stick, and bay leaf in a saucepan. Bring to a gentle boil and stir until sugar dissolves, about 2 minutes.
04 -
Layer beets and onion in clean pint jars, leaving 1/2 inch headspace.
05 -
Pour the hot brine over the beets to cover completely. Let cool to room temperature, then seal and refrigerate.
06 -
Refrigerate at least 24 hours for best flavor. Use within 3 weeks.