Instructions
Prepare four hot pint jars and lids. Wash peppers, remove stem ends, and slice into 1/4-inch rings.
Combine cider vinegar, water, and salt; bring to a boil.
Place 1/2 tablespoon celery seed and 1 tablespoon mustard seed in each hot pint jar. Fill with pepper rings.
Cover with boiling pickling liquid, leaving 1/2-inch headspace. Remove bubbles, adjust headspace, wipe rims, and apply lids.
Process pints for 10 minutes at 0–1,000 ft, 15 minutes at 1,001–6,000 ft, or 20 minutes above 6,000 ft. Cool 12 to 24 hours, check seals, and shake before serving to disperse spices.