Combine tomatoes, onion, and garlic in a large stock pot and bring to a boil; lower heat and simmer 30 minutes or until vegetables are very soft. Working in batches, puree vegetables until smooth with Harvest Pro food mill or in the bowl of a food processor.
2. Step
Return tomato mixture to the pot and add remaining ingredients, bring to a boil over high heat, stirring frequently. Lower heat and simmer until thickened and darker in color, about 1½–2 hours, stirring occasionally to prevent scorching.
3. Step
Prepare boiling water canner while sauce is cooking. Heat jars in simmering water until ready to use. Do not boil. Wash lids in warm soapy water and set aside with bands.
4. Step
Ladle hot BBQ sauce into a hot jar leaving a ½-inch headspace. Remove air bubbles. Wipe jar rim. Center lid on jar and apply band; adjust to fingertip tight. Place jar in boiling water canner. Repeat until all jars are filled.
5. Step
Process jars for 20 minutes, adjusting for altitude. Turn off heat, remove lid, let jars stand 5 minutes. Remove jars and cool 12–24 hours. Check lids for seal. They should not flex when center is pressed.
