Wash apples, core, and chop (peel if desired).
Add to large pot with water. Cover and simmer 30–45 minutes until soft.
Blend or mash to your preferred texture.
Fill hot jars, leaving 1/2" headspace.
Wipe rims, apply lids, and process: 20 min for pints, 25 min for quarts.
Cool for 12–24 hours. Check seals, label, and store.