Pick your fresh tomatoes.
Take out a big old stockpot and chop up 6 tomatoes. I chopped mine into thirds.
Cover the bottom of the stockpot with one layer of chopped tomatoes. Take a potato masher and squish them to get their juices running. Turn the pot on medium-high.
Once the tomatoes begin to boil, add 6 more chopped tomatoes. Stir frequently to prevent scorching, but also make sure the tomatoes continue to boil.
Continue adding chopped tomatoes, one layer at a time, until you’ve added all your tomatoes or you’re in danger of overflowing your pot. If you’re working with a larger batch, you can use two large pots.
Mash each layer well as you continue to stir and allow tomatoes to boil.
Continue to boil for approximately 10 minutes. You want all the tomatoes cooked and mushy, with their glorious juices released.
Remove cooked tomatoes from heat. Put mixture through a fine sieve (which is my preference) or a food mill positioned over a large mixing bowl, preferably with measurements so you know how many cups of sauce you end up with.
Now that you know how many cups of sauce you have, you can gather the appropriate number and size jars for canning.
Put the strained tomato mixture back into the stockpot and bring to a boil. Turn down to a simmer and allow it to reduce down to the desired thickness. I reduced mine for about 40 minutes and let about an inch of liquid evaporate.
Meanwhile, prepare your jars, gather your lids, and either your water bath canner or your pressure canner.
Add 1 Tablespoon bottled lemon juice to each pint jar, 2 Tablespoons lemon juice to each quart jar.
Add 1/4 teaspoon salt to each pint jar, 1/2 teaspoon salt to each quart jar.
Add 1/2 teaspoon dried basil to each pint jar, 1 teaspoon dried basil to each quart jar.
Fill jars with tomato sauce up to a 1/2-inch headspace for water bath canning and 1-inch headspace for pressure canning.
Run a spatula around the jar circumference to remove air bubbles. Add more tomato sauce if needed to keep 1/2-inch or 1-inch headspace depending upon your method of canning.
With a damp clean cloth, wipe the rim of the jar clean. Place on lids and screw down the bands until resistance is met, then to fingertip tight.