Cut the tomatoes in half or quarters. Cut the celery into 3-4 pieces, thinly slice the carrots, peel and quarter the onion, peel the garlic. Honestly, you don’t have to cut the tomatoes, but cutting them helps them cook a little bit faster.
Place all the ingredients EXCEPT the lemon juice in a large stockpot. Bring to a boil. Reduce to a simmer, and keep cooking, for about 30-45 minutes, until all the vegetables are soft.
If you are using beets and carrots, they take a little bit longer to cook through and get soft, so you will need to cook the juice a little bit longer. If you are just using tomatoes, onions, garlic and celery, 30 minutes should be enough time.
Use a potato masher or a immersion blender to mash up all the vegetables. This will get you a lot more juice and it will be faster to strain. If you have a food mill, you can use that instead. Pour in the lemon juice.
The lemon juice will help to make sure there is enough acidity to be at a safe ph level for canning. The lemon juice won’t change the flavor. Although almost all tomatoes will already be high enough in acidity for canning – it is a simple extra step to ensure safety.
Strain the tomato juice through a fine mesh sieve, pushing on the vegetable solids to extract as much juice as possible. Taste the tomato juice and add more salt and/or sugar if needed.
If you don’t sterilize the jars, the juice will keep for about 1-2 weeks in the refrigerator. You can also freeze tomato juice for up to 1 year.
Sterilize your canning jars and lids. Wash the jars and lids in hot and soapy water. Then, place the glass jars in a 200 degrees Fahrenheit oven for about 15 minutes. Using your dishwasher works great too.
For the lids, I usually bring a pot of water to a boil, take it off the heat and let the lids stay in the boiling water for 10-15 minutes also.
Pour the strained juice into the sterilized jars, leaving about 1/2″ of space at the top. Wipe the rims of the jars so that they seal properly and top with the lids.
Out of this amount of tomatoes and vegetables, I was able to get 4 quarts plus a little bit extra. The amount will be slightly different, depending on how juicy the tomatoes are that you are using.
Place sealed jars in boiling water bath for about 10 minutes. (Make sure you place a towel at the bottom of the pot, so that the jars are not directly touching the pot.) Remove from the water and cool completely.
Store open jars of juice in the refrigerator for up to 1 week.