Directions

1. Wash and rinse pint canning jars; keep hot until ready to use. Prepare lids and bands according to manufacturer’s directions.
2. To peel onions, place a few at a time in a wire-mesh basket or strainer, dip in boiling water for 30 seconds, then remove and place in cold water for 30 seconds. Cut a 1/16th-inch slice from the root end, and then remove the peel and 1/16th inch from the other end of the onion.
3. Combine vinegar, water, salt and sugar in an 8-quart Dutch oven or stockpot. Bring to a boil and boil gently 3 minutes. Add peeled onions and bring back to a boil. Reduce heat to a simmer and heat until the onions are half-cooked (about 5 minutes).
4. Meanwhile, place 2 teaspoons mustard seed and 1 teaspoon celery seed in the bottom of each clean, hot pint jar. Fill hot jars with the hot onions, leaving 1-inch headspace. Cover with hot pickling liquid, leaving ½-inch headspace. Remove air bubbles and adjust headspace if needed. Wipe rims of jars with a dampened, clean paper towel; adjust two-piece metal canning lids.
5. Process in a boiling water canner, as recommended in Table 1. Let cool, undisturbed, 12 to 24 hours and check for seals.

Allow pickled onions to sit in processed jars for 3 to 5 days before consuming for best flavor development.