This will be a long post, but I'll try to make it simple. I took lots of pictures, so hopefully that helps to break it up a little. As always, if you are confused by anything or have any questions, feel free to leave me a comment here, through e-mail, or on Facebook!
lemons or bottled lemon juice
canning pot with lid
large non-reactive pot (such as stainless steel)
canning rings and lids (either the ones that come with the jars or reusable lids)
Supplies Optional, but Recommended:
canning rack (often comes with a canning pot)
The first thing to do is to sterilize the jars. I just use the canning pot for this. Place the jars in the pot, fill the pot with enough water to cover the jars, and turn the stove on low - they'll be on the heat long enough to get sterilized.
At the same time, have the canning rings and lids sterilizing in the saucepan. Again, put the pot over low heat and just leave it. Don't let this one come to a boil.
Now it's time to work with the tomatoes. First, the tomatoes need to be peeled. You can choose to leave the skin on, but I don't recommend it as you will have chewy bits in your tomato sauce. To peel the tomatoes, get a large pot of water boiling. Once it has come to a boil, throw in 5 or 6 tomatoes. Leave them in for 45 seconds to 1 minute.
Don't leave the tomatoes in the boiling water any longer than that. Remove immediately to a bowl of ice water. I just plugged up one side of my sink and filled it with cold water and a few pieces of ice.
After just a few seconds the tomatoes will be cool enough to touch. Pick up one, score it with a knife, and the skin should peel right off.
Repeat with all the tomatoes. I didn't have a large enough bowl to set all the tomatoes in, so here's what I ended up with...
Next, take each tomato, cut it in half, and then cut out the stem and other hard or bad spots.
Take each half and give it a squeeze. This removes some of the water (which would need to be cooked down anyway) and most of the seeds. Don't worry about removing all of the seeds.
Place the squeezed tomatoes in a colander in the sink that way they can continue to drain while you cut and squeeze out the rest of the tomatoes.
After all the tomatoes are ready, it's finally time to make tomato sauce! Dump the tomatoes in a large non-reactive pot. I was able to do all 25 pounds of tomatoes in two batches.
Now we just have to wait for the tomatoes cook down. Cook over medium heat. Use a large spoon or a potato masher to crush them down. I used an immersion blender, because it's really fast and makes the sauce nice and smooth. Cook the tomatoes until they have reduced by 1/3 to 1/2, according to your preference for thickness. This will take anywhere between 1 and 2 hours, depending on how big your pot is. Here's mine after about 30 minutes (and before I used the immersion blender).
When your sauce is nearly ready, prep the area for canning. Remove your canning jars with the jar lifter and put them onto a towel. Bring the canning pot up to a boil. Use the tongs to remove the canning rings and lids from the saucepan.
Squeeze the lemons (or use bottled lemon juice). Add the lemon juice to each jar as follows:
Half-Pint jars - 1/2 Tablespoon
Pint jars - 1 Tablespoon
Quart jars - 2 Tablespoons
Now, very carefully add the tomato sauce to the jars. It's easier to ladle some tomato sauce into a large measuring cup with a spout first to do this. Fill each jar to within 1/4 inch from the top. Use the funnel to prevent messes.
Now add the canning rings and lids. If you are using the traditional lids that come with the jars, just place the lid on top and then screw the ring on. You can also get reusable BPA-free canning lids from Tattler Reusable Canning Lids. If you are using these, place on the rubber ring and plastic lid, then screw on the metal ring but do not overtighten! These must be allowed to vent!
Once all the jars are ready, use the jar lifter to place them back into the canning pot. Put the lid on the pot and process as follows:
Half-Pint jars - 30 minutes
Pint jars - 35 minutes
Quart jars - 40 minutes
After time is up, pull on the handles of the canning rack to remove all the jars at once (or use the jar lifter). Set the rack on a towel.
If you used the Tattler Reusable Canning Lids, tighten the lids the rest of the way as soon as they come out. Then, do not disturb the jars. If you used traditional lids, you should hear them pop. I used some Tattler lids and some traditional lids (these will be gifts and I know I'll never get them back!). I heard the regular lids pop right away.
Once the jars have cooled, remove the metal rings. The way to check the seal on the Tattler lids is to pick up the jar by the lids. If it picks up and doesn't come off, it is sealed! I had no problem using the Tattler lids, every one of my jars sealed successfully.
I ended up with 4 quarts, 8 half-pints (1 broke), and a little sauce left over.
This was a time-consuming project, but it was so much fun. There's really no greater sense of accomplishment than making and canning your own food. I did get to taste the tomato sauce, and it was delicious! I hope you enjoy the experience as much as I did!
Printable: Homemade Tomato Sauce and Canning How-To