How to Can Those Extra Garden Tomatoes

With a little practice, this easy old-school food-preserving technique can keep your family enjoying the tastes of summer all through the winter.

August 20, 2009

You can do it: Preserve some of your tomatoes now, and you'll be glad later.

RODALE NEWS, EMMAUS, PA—There's been a huge movement this year to growing your own food; even the White House started an organic garden! If you're one of the many new gardeners on the market, you may be up to your knees in juicy tomatoes this time of the year—and wondering what exactly you should do with them (assuming the blight that struck earlier in the year didn't wreck your crop). Canning some of those tomatoes is a great solution to a backyard tomato surplus. So we spoke with Aimee Good, CSA farmer at Quiet Creek Farm, a commnity-supported agriculture program at the Rodale Institute in Pennsylvania, to give us step-by-step directions and tips. Good promises that canning is pretty easy, once you get the hang of it. Ready to give it a try? Here's what you'll need for water-bath canning, which is commonly used for high-acid foods like tomatoes.



• A large pot with a lid, or a canner (available online at places like Lehman's)

• Glass canning jars, lids, and screwbands (commonly available at grocery stores and online)

• A jar funnel, to fill jars easily and cleanly

Tomato prep:

• If you'd like, you can peel the skins before canning, but you don't have to. If you opt to skin your 'maters, dip them first in boiling water to loosen the skins, then plunge them in cold water. Drain, peel, and core. "I prefer to not peel or remove seeds from my tomato products, except perhaps for tomato soup, for which I use a food mill," says Good. "It makes them much easier to process, and we never mind eating the seeds and skins."

Jar prep:

• To sterilize your canning jars, see the Nickel Pincher's canning recipes.

How to can quartered tomatoes:

• Start with only perfect tomatoes. Cut into quarters. Cut out cores. Place in pot, and cook over medium heat until level of juice meets level of tomatoes.

• Pack into hot, sterilized jars, leaving ½ inch of headspace. Add acid to jars to ensure high levels: For quart jars, add 4 teaspoons of lemon juice OR 2 tablespoons of vinegar OR ½ teaspoon citric acid per jar. Use half as much per pint jar.

• Wipe rims clean then close jars with hot, sterilized lids. Place into a boiling-water bath for 40 minutes for pint jars, 45 minutes for quart jars, according to the USDA (the water should stay boiling the whole time). If you live at an altitude above 1,000 feet, you'll have to add more time five to 15 minutes to the process, according to USDA. "I make lots of these and use them for soups and stews all winter long," Good explains.

Recipe: Aimee's Great Pasta Sauce for canning:

• Use paste tomatoes from the garden; they have lots of meat and little juice. You can avoid needing to cook the sauce down for a day or so by using roasted tomatoes to thicken it. To roast them, cut the tomatoes in half and place on baking trays, cut-side down. Roast in a 350-degree oven for 20 to 25 minutes, until the skin is wrinkled but before it is browned. Drain the juice.

• Puree tomatoes in food processor. This will give you a nice thick tomato paste from the beginning, and roasting also enhances the flavor. "If you want to remove skins, you can easily peel them from roasted tomatoes, but I find that they become fairly well pureed in the food processor," says Good.

• Add salt, pepper, chopped herbs, and the seasonings of your choice. Good likes to add red wine and a dash of Worcestershire sauce.

How to can Aimee's Great Pasta Sauce:

• Place sauce in sterilized jars, leaving ½ inch of headspace, and process in a boiling-water bath for 45 minutes. "Salsas, ketchups, chili sauce, tomato soup, tomato paste…there are many possibilities with this most beloved fruit," she says. For more recipes, she suggests the book Stocking Up III: The All-New Edition of America's Classic Preserving Guide(Rodale, 1986). You can also find more information for free by downloading the
USDA's Canning Guide

Aimee's Inside Canning Tips:

• Certain foods, such as pasta sauce, can be prepared one day, cooled and refrigerated overnight, and then canned the next day. Be sure to reheat the food to boiling before attempting to can or you will break the jars.

• Have plenty of time, a clean workspace, and everything you need before you begin.

• Check lids after jars have cooled. Try one of the following methods to test the jar seal after cooling the jars for 12 to 24 hours: Remove the screw bands and press the center of the lid; if it springs up, the lid isn't sealed. Or, you can tap the lid with a teaspoon; if it makes a dull sound, it is not sealed. If it’s correctly sealed, it will make a high-pitched ringing sound.

• Remove screwbands from the jars before storing the food. This way if something did not work and spoils, the lid will be pushed off as it ferments. (Better than exploding jars.)

• Store jars in a cool, dark place for optimum nutrient retention. Ideal temp is 50 to 60 degrees F.

• Don’t discard the liquid in the jars after eating the food, as some of the nutrients from the fruit/vegetables are in the liquid. Use vegetable liquid for soups, fruit liquid for smoothies. "I like to reuse my pickle liquid to make pickled eggs—a great snack. Just hard-boil eggs and put in the jar with pickle juice. Store in fridge. After a few days, you will have a pickled egg. Eat with salt and mustard!"

• Label your jars. There is often a place on the lid.

• You can reuse screwbands from year to year, but you should definitely buy new lids.

• Buy a good book on canning to help you along, and/or work with an experienced friend. Start with foods that you buy often, or that your family especially enjoys.