BBQ Sauce for Canning

20 cups chopped cored peeled tomatoes
2 cups finely chopped onions
3 garlic cloves, finely chopped
1 tablespoon hot pepper flakes
1 tablespoon celery seeds
1 1/2 cups lightly packed brown sugar
1 cup white vinegar
1/3 cup lemon juice
2 tablespoons salt
1 1/2 tablespoons nutmeg
1 tablespoon dry mustard
1 teaspoon ground ginger
1 teaspoon ground cinnamon

In a saucepan combine onions, tomatoes, garlic, pepper flakes, and celery seeds. Bring to a boil over high heat, stirring constantly. Reduce heat, cover and boil gently until vegetables soften, about 30 minutes.
Working in batches, transfer mixture to a sieve placed over a galss or stainless steel bowl and press with he back of a spoon to extract all liquid and pulp. Discard solids.
Return liquid and pulp to saucepan. Add brown sugar, vinegar, lemon juice, salt, nutmeg, mustard, ginger and cinnamon. Return to boil over medium-high heat, stirring occasionally. Reduce heat and boil gently, stirring frequently, until mixture is thickened to the consistency of a thin bbq sauce, about 30 minutes.
Prepare canner, jars and lids. Jar the sauce leaving 1/2 in headspace. Remove air bubbles, wipe rim, place lids and bands.
Process 20 minutes.