Step 1: Prepare the Tomatoes

• Wash and quarter tomatoes. In a large pot, combine tomatoes, onions, and 1 cup of water. Cook over high heat, stirring occasionally, until the tomatoes break down and release a lot of the water.
  10 Pounds Tomatoes, 1 Cup Onions, 1 Cup Cold Water

Step 2: Strain and Blend

• Run the tomato mixture through a food mill or fine mesh strainer to remove seeds and skins. You can also use an immersion blender or a food processor for a smoother consistency.

Step 3: Cook Down the Ketchup

• Transfer the strained tomato puree to a stainless steel saucepan or heavy bottom pot. Add apple cider vinegar, white vinegar, brown sugar, salt, black pepper, garlic powder, and onion powder.
  1 Cup Apple Cider Vinegar, 1/2 Cup White Vinegar, 1 Cup Granulated Sugar, 1 Tablespoon Pickling Salt, 1/2 Teaspoon Black Pepper, 1 Teaspoon Garlic Powder, 1 Teaspoon Onion Powder
• Place the cinnamon sticks, whole clove, and celery seeds in a spice bag and add it to the pot. Bring the mixture to a boil over high heat, then reduce to medium heat and simmer, stirring occasionally, until it reduces to half its original volume.
  3 Cinnamon Sticks, 1 Whole Clove, 1 Tablespoon Celery Seeds

Step 4: Thicken and Season

• Stir in tomato paste, cayenne pepper, and lemon juice. Adjust seasoning to taste. Continue cooking until the ketchup reaches the desired consistency. If it’s too thin, simmer longer. If too thick, add a bit of water. Using a hand blender or high-speed blender can help smooth out the ketchup.
  1/2 Cup Tomato Paste, 1 Juice of 1 Lemon, 1/2 Teaspoon Cayenne Pepper

How to Can Homemade Tomato Ketchup

Step 1: Prepare Canning Jars

• Wash jars, screw bands, and canner lid in hot soapy water. Sterilize jars. The easiest way is to submerge them in boiling water for 10 minutes or run them through a hot dishwasher cycle. Place jars in a water bath canner to stay warm.

Step 2: Fill the Jars

• Ladle hot ketchup into hot jars, leaving 1/2 inch headspace. Use a kitchen towel to wipe jar rims and remove air bubbles. Secure lids and screw bands.

Step 3: Process in a Water Bath

• Place jars in a water bath, ensuring they are covered by boiling water. Process for 15 minutes (adjusting for altitude). Remove jars and let them cool in a dark place for 12-24 hours. Check seals before storing jars in an airtight container.