Canning tomatoes? Don’t sweat it

By Andrea Weigl - The News & Observer

Harold Golomb stocks his tomato booth during a previous Pittsotn Tomato Festival.

Bill Tarutis File Photo | For Sunday Dispatch

I love canning but even I was intimidated by preserving tomatoes.

So earlier this month, I bought 50 pounds of plum tomatoes at the farmers market to try to tackle my fears.

Mainly, I was daunted by the amount of work involved. Canning is already a hot sweaty business with that huge pot of boiling water steaming up the kitchen. With tomatoes, it’s worse because you have drop the fruit in boiling water for 30 seconds to 1 minute to remove the skin. That just increases the sweatiness factor by 10. And it’s not like you can get away with only processing five pounds. With tomatoes, if you are going to do all that work, it’s better to can 10, 20 or 30 pounds.

So first, I checked in with a couple experts to find out if there are easier ways.

Sarah Page is the culinary marketing manager at Jarden Home Brands, which makes the popular Ball canning jars. Jarden has recently updated its go-to canning cookbook, “The All New Ball Book of Canning and Preserving.”

Page’s take-home advice: Roast the tomatoes instead of blanching them. The skins slip off easily and, Page notes, roasting helps concentrate the flavor. I found several recipes that take advantage of this method: a roasted tomato marinara sauce, a charred tomato, pepper and onion salsa and oil-packed slow-roasted tomatoes that can be stashed in the refrigerator.

Then I talked to Domenica Marchetti, who has written a number of Italian cookbooks and has a new one, “Preserving Italy.” Her advice: do as the Italians do. “When people do this in Italy, the whole family gets involved. It becomes an event,” Marchetti explained. The picking of the tomatoes, the preparation and the processing is all done outside.

While I didn’t rope my family into the task, I did lug my canning pot into the yard to heat up on a turkey fryer base. With the canning pot outside and only roasting, broiling and a little simmering happening in the kitchen, it barely got steamy.

I only have two pounds of tomatoes left from that 50-pound box. Imagine what I could do if I got some friends or family involved?

Basic water bath canning instructions

There are two steps to canning. First you must sterilize the jars, then you have to process them when filled.

1. To sterilize, wash jars, lids and screw bands in warm, soapy water. Rinse. Set aside. Place rack in the bottom of the canner. Place jars on top of rack. Fill canner with water until the jars are covered by about 1 inch. Bring water to a simmer.

2. Prepare recipe per instructions. Remove jars from canner. Fill jars, leaving either a 1/4-inch or 1/2-inch head space, as the recipe dictates. Insert a small spatula or similar slender nonmetallic object into the jar two or three times to help release air bubbles. Wipe the jar’s rim with a damp, clean cloth or paper towel.

3. Center lid on top of jar. Place screwband on the jar. Twist screwband until fingertip-tight.

4. Place jars back into canner, place lid on canner and bring water to a full rolling boil over high heat. Let jars process for how ever long the recipe states. Turn heat off, remove lid and let jars stand in the water for 5 minutes. Then remove jars from canner. Let jars sit upright on a towel. Let cool, undisturbed, for 24 hours.

New crop of canning books

— “The All New Ball Book of Canning and Preserving,” (Oxmoor House, 2016): An update of the classic go-to canning tome. All the recipes are tested by food scientists for safety. (The only other entity that can make such a claim is the National Center for Home Food Preservation at the University of Georgia.) The book covers water bath canning, fermenting, pressure canning, freezing, dehydrating and even curing and smoking. It is a must-have for beginners and experienced cooks will find it useful as well.

— “Canning for a New Generation,” by Liana Krissoff (Abrams, 2016): This is an updated and expanded version of Lianna Krissoff’s 2010 book, now with 250 recipes. It tackles fruits and vegetables by season and is packed with inspiring recipes for what to do with your pantry of canned goods to get dinner and dessert on the table. My favorite chapter is “Baked and Creamy Things to Put Preserves On.”

— “Preserving Italy,” by Domenica Marchetti. (Houghton Mifflin Harcourt, 2016): If you enjoy preserving food and have a fondness for Italian cuisine, this is the book for you. Italian food expert Domenica Marchetti walks beginners and experienced canners alike through preserving in oil, vinegar and alcohol, as well as making sweet preserves, infused oils, vinegars and condiments. She even tackles fresh cheeses and simple cured meats. Of course, there’s a whole chapter on tomatoes and sauce.

Oven-roasted marinara

Roasting tomatoes and onions intensifies the flavor, drawing out the inherent sweetness of both. This is a versatile base sauce that can be used on its own or as the starting point for other sauce variations. From “The All New Ball Book of Canning and Preserving,” (Oxmoor House, 2016).

20 pounds plum tomatoes

1 1/2 cups chopped onion (about 2 medium)

Vegetable cooking spray

1 cup dry red or white wine

1 tablespoon salt

1 tablespoon dried oregano

2 teaspoon black pepper

6 garlic cloves, minced

2 bay leaves

2 teaspoons citric acid or 1/2 cup bottled lemon juice

Preheat oven to 375 degrees. Cut tomatoes into halves or quarters, as necessary, to create uniform size. Arrange tomatoes in a single layer on large rimmed baking sheets. Bake, in batches, at 375 degrees for 45 minutes or until tomatoes are very soft and beginning to brown. Cool.

Spread onion on a separate large baking sheet coated with cooking spray. Bake at 375 degrees for 20 minutes or until onions are golden brown, stirring occasionally.

Press tomatoes, in batches, through a food mill into a large bowl; discard skins and seeds. Place tomato puree and caramelized onion in a large stainless steel or enameled stock pot. Stir in wine and next 5 ingredients. Bring to a boil; reduce heat, and simmer, uncovered, 15 to 20 minutes or until reduced to desired texture. Remove and discard bay leaves. Stir in citric acid or lemon juice.

Ladle hot marinara sauce into a hot jar, leaving 1/2-inch headspace. Remove air bubbles. Wipe jar rim. Center lid on jar. Apply band, and adjust to fingertip-tight. Place jar in boiling-water canner. Repeat until all jars are filled.

Process jars 40 minutes, adjusting for altitude. Turn off heat; remove lid, and let jars stand 5 minutes. Remove jars and cool.

Yield: 8 pints and 4 quart jars.

Charred tomato and chile salsa

If you want to make it hotter, use a hotter variety of chile rather than adding more jalapeños, lest the additional nonacid ingredients push the pH too high for boiling-water-bath canning. From “Canning for a New Generation,” by Liana Krissoff (Abrams, 2016).

6 pounds plum tomatoes, halved lengthwise, cores cut out

8 ounces red jalapeño chiles (about 10 small), stemmed and halved lengthwise

2 ounces garlic (about 12 cloves), peeled

1 pound onions (about 2 small), peeled and quartered

1 cup cider vinegar (5 percent acidity)

1 tablespoon salt, or more to taste

2 tablespoons sugar

Preheat the broiler to high and set a rack about 4 inches from the heating element. Line a rimmed baking sheet with aluminum foil.

Working in batches, put the tomatoes cut side down on the baking sheet and broil for about 10 minutes, until the skin is blistered and black in places. Put the tomatoes in a large bowl and set aside. Broil the chiles, garlic and onions until blackened. When the tomatoes are cool enough to handle, pull off the skins and return only the charred bits to the bowl. In three batches, put all the broiled vegetables in a blender and pulse until just coarsely chopped; transfer to a wide 6- to 8-quart preserving pan and add the remaining ingredients. Bring to a boil and boil for 5 minutes.

Using a jar lifter, remove the hot jars from the canning pot, carefully pouring the water from each one back into the pot, and place them upright on a folded towel.

Spoon the hot salsa into the jars, leaving 1/2-inch headspace at the top. Use a damp paper towel to wipe the rims of the jars, then put a flat lid and ring on each jar, adjusting the ring so that it’s just finger-tight.

Return the jars to the water in the canning pot, making sure the water covers the jars by at least 1 inch.

Bring to a boil and boil for 40 minutes to process. Remove the jars to a folded towel and do not disturb for 12 hours. After 1 hour, check that the lids have sealed by pressing down on the center of each; if it can be pushed down, it hasn’t sealed and the jar should be refrigerated immediately. Label the sealed jars and store.

Yield: 5 pint jars.

Bottled whole tomatoes

Bottling tomatoes only makes sense if you use good, ripe summer tomatoes that are meaty and flavorful. If you are a gardener, growing your own tomatoes is your best bet. Otherwise, look for ripe, unblemished plum tomatoes at your local farmers’ market. Some markets now offer San Marzano-style tomatoes, which are typically longer than plums with a point on the bottom. They are the classic Italian tomato for sauce and canning. Recipe testing notes: If you aren’t as forceful about packing the tomatoes into the jars, have some extra puree on hand. Our test produced six quart jars and needed 2-3 extra cups of puree. Use widemouth jars. Adapted from “Preserving Italy,” by Domenica Marchetti. (Houghton Mifflin Harcourt, 2016).

4-7 cups best-quality commercial tomato puree

8 pounds ripe plum tomatoes

8-12 tablespoons freshly squeezed or bottled lemon juice

Bring a large stockpot of water to a rolling boil and have ready a large bowl of ice water. In a small saucepan, bring the puree to a simmer over medium heat. Reduce the heat to low and cover to keep warm.

Cut a small “X” in the bottom of each tomato. Plunge the tomatoes, in batches if necessary, into the boiling water and boil for 1 minute. Use a large skimmer or slotted spoon to transfer them to the bowl of ice water. Drain the tomatoes, then peel and discard the skins.

Add 2 tablespoons lemon juice to each jar. Pack the tomatoes tightly into each jar, fitting in as many as possible without squishing them. Funnel the puree into the jars, dividing it evenly, leaving 1/2-inch headspace.

Screw the lids on tightly and process for 45 minutes in a boiling-water bath. Remove the jars and set them upright on a clean kitchen towel. Let the jars cool to room temperature before storing in a cool, dark place for up to 1 year. Refrigerate after opening and use within 1 week.

Yield: 4 quarts

Oven roasted tomatoes in oil

Roasting tomatoes in a slow (low-heat) oven deepens their flavor and enhances that delicious savory quality known as umami. This technique can turn even anemic out-of- season tomatoes into something special. Even if all you have on hand is a box of pasta and a jar of these tomatoes, you have the fixings for a delicious dinner. I also use these as a topping for bruschetta or crostini, as a sauce for grilled or sautéed fish, or as a flavor booster for soups and stews. Because these tomatoes retain some juice, they won’t keep as long as those that are dried completely in the sun or in the oven. Store them in the fridge and be sure to keep them submerged in olive oil to prolong their freshness. Adapted from “Preserving Italy,” by Domenica Marchetti. (Houghton Mifflin Harcourt, 2016). Recipe tester’s notes: I used cherry tomatoes, but checked them after 2 1/2 hours in the oven.

2 1/2 pounds ripe Roma (plum) tomatoes, about 10 large

3 tablespoons extra-virgin olive oil, plus more to cover

1/2 teaspoon fine sea salt

Freshly ground black pepper

A few thyme sprigs and/or crushed fennel seeds (optional)

Preheat the oven to 275 degrees.

Cut the tomatoes in half lengthwise and arrange them on a large rimmed baking sheet lined with parchment paper or aluminum foil. Drizzle the olive oil over the tomatoes and season with the salt and a generous grinding of pepper. Scatter the thyme and fennel seeds over the top, if using.

Slow-roast the tomatoes until they are partially collapsed, crinkled, and somewhat dried out, but still soft and juicy, even a little caramelized, about 3 hours. Be sure to check on them from time to time to make sure they are cooking evenly and are not developing any scorched spots. Rotate the pan if necessary for even cooking. Let the roasted tomatoes cool completely.

Pack the tomatoes into a glass jar with a tight-fitting lid. Pour in enough olive oil to cover them and store in the refrigerator for up to 2 months. As you use the tomatoes, top off those in the jar with oil to keep them covered.

Yield: 1 pint.

Harold Golomb stocks his tomato booth during a previous Pittsotn Tomato Festival. Golomb stocks his tomato booth during a previous Pittsotn Tomato Festival. Bill Tarutis File Photo | For Sunday Dispatch

By Andrea Weigl

The News & Observer

Reach the Sunday Dispatch newsroom at 570-655-1418 or by email at

Reach the Sunday Dispatch newsroom at 570-655-1418 or by email at

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