As promised, here is my ketchup recipe. I tripled this recipe, which resulted in 16 half-pints. It took me approximately 6 hours to boil down the ketchup; it takes less time if you are doing a smaller batch.
1 stick cinnamon, broken
1 tsp. whole cloves
1 tsp. mustard seed
1 tsp. celery seed
1 cup vinegar
8 pounds tomatoes
1 cup chopped onion
1/4 teaspoon cayenne pepper
1 cup sugar
1 tbs. salt
Place cinnamon stick, cloves, mustard seed and celery seed in a spice bag; add to vinegar. Bring vinegar and spices to a boil; remove from heat and let stand.
Peel, core, quarter, and seed tomatoes.* Combine tomatoes, onion and cayenne pepper. Simmer until soft. Puree using a food processor or food mill. Add sugar, stirring until dissolved. Bring to a boil. Reduce heat and simmer until reduced by half. Remove spice bag from vinegar. Add vinegar and salt to tomato mixture. Simmer until desired consistency.
Freezer instructions: Cool. Ladle ketchup into can-or-freeze jars or plastic freezer boxes, leaving 1/2-inch headspace. Seal, label and freeze.
Canning instructions: Ladle hot ketchup into hot jars, leaving 1/4-inch headspace. Adjust two-piece caps. Process 10 minutes in a boiling water canner.
*If you have a food mill that removes skin and seeds, there is no need to peel and seed tomatoes.