Combine ingredients in a large saucepan. Bring to a boil, then reduce heat and simmer, stirring frequently until thick (about 1 hour). Ladle hot mixture into pint jars, leaving 1/2-inch headspace. Adjust lids and process in boiling-water canner for 15 minutes at 0–1,000 feet elevation, 20 minutes at 1,001–6,000 feet, and 25 minutes above 6,000 feet.