These chopped tomatoes take a bit more time to "put up" than do Whole Peeled Tomatoes, but the ready-to-use, almost-sauce results are a delight to open on a cold winter night. The method below is from Food in Jars by Marisa McClellan. These tomatoes are quickly blanched in hot water, peeled, chopped, cooked down a bit, poured into jars, covered, and boiled to seal the jars. The process takes some time, but doesn't require any special skills. Seriously, anyone with an excess of ripe tomatoes can do it.
Note: While in pretty much every other instance I can think of, I call for fresh lemon juice, when it comes to canning tomatoes you want to use bottled because it has a standardized and consistent acid level that you want to keep the tomatoes edible. See more Canning Safety Tips. You may also want to check out this list of canning equipment.
- 10 pounds ripe whole Roma or other low-moisture tomatoes
- 6 Tablespoons bottled lemon juice
- 6 pint jars with sealable lids
- Bring a large pot or canning kettle of water to a boil. While the water works on coming to a boil, use a sharp knife to cut a small "x" in the bottom of each tomato. Once the water is boiling, put the tomatoes in. Cook them for about a minute, then lift them out with a slotted spoon. Put the tomatoes directly into a large bowl of ice water or on a large baking sheet so they can cool quickly.
- As soon as the tomatoes have cooled off enough so that you can handle them easily, use a sharp paring knife to remove (and discard) the tomato skins. Having blanched them, the skins should slip right off without too much fuss.
- Chop the tomatoes, reserving as many of their juices as possible (I find setting a cutting board inside a rimmed baking sheet or roasting pan a good way to catch all of the juices). Put the tomatoes and their juices in a large pot and bring to a boil. Reduce heat to maintain a simmer and cook, stirring frequently, until they thicken up, about 30 minutes.
- Meanwhile, bring the water back to a boil, put the jars in the canning rack, and boil the empty jars for 10 minutes to sterilize them. Put the lids in separately, also for 10 minutes, to soften the sealant.
- Remove the jars from the water (empty any water back into the pot). Put a kettle of water on to boil. While the water is boiling, put 1 Tbsp. bottled lemon juice in each jar. Fill the jars evenly with the tomatoes (I find a large mouth funnel extremely useful for this), leaving 1/2 inch of head space at the top of the jars. Wipe the edges of the jars clean and place the lids and rims on the jars, set the jars in the canning rack, and lower them into the boiling water in the canning kettle or other large pot. Cook, with the water boiling the whole time, for 40 minutes.
- Remove cans from their water bath and set them on a counter to dry and cool. Store jars in a cool, dark place until ready to use.
Want an overview of the process? See 10 Easy Steps for Home Canning.
Want whole tomatoes? See How to Can Whole Tomatoes.