Prepare the Tomatoes: Begin by blanching the tomatoes. Bring a large pot of water to a boil. Make small “X” slashes on the bottom of each tomato. Place the tomatoes into the boiling water for 30-60 seconds or until the skins begin to peel off. Remove and transfer the tomatoes to ice water.
Peel and Chop: Peel off the skins and remove the stems. Chop the tomatoes into chunks and set aside.
Cook the Soup Base: In a large stockpot, heat the olive oil or butter over medium heat. Add the chopped onion and garlic and sauté until softened, about 5 minutes. Add the chopped tomatoes, broth, salt, pepper, and optional herbs (basil, oregano). Simmer the mixture for 30-40 minutes, allowing the flavors to blend.
Blend the Soup: Once the soup base has simmered and softened, use an immersion blender or transfer the soup to a regular blender. Puree until smooth. If using a regular blender, blend in batches.
Add Acidity and Sugar: Return the soup to the pot, stir in the lemon juice, and adjust the seasoning with sugar (if desired) to balance the acidity of the tomatoes.
Canning Process: Prepare your canning jars by sterilizing them. Ladle the hot tomato soup into the hot jars, leaving 1-inch headspace at the top. Wipe the rims clean with a damp cloth, then seal with the canning lids and rings.
Process the Jars: Place the sealed jars into a water bath canner and process for 35-45 minutes. Ensure the jars are completely submerged in water and maintain a rolling boil. After processing, carefully remove the jars and set them aside to cool.
Check Seals and Store: Once cooled, check that the seals are intact by pressing on the center of each lid. If the lid doesn’t pop back, the jar is properly sealed. Store the sealed jars in a cool, dark place.
