How to Preserve Tomatoes in 7 Ways

Summer tomatoes are sweet and juicy, but like summer, they are gone fast unless preserved. There are many easy ways to preserve summer tomatoes at home so you can enjoy their flavor when summer becomes a distant memory. Whether you are canning, drying, freezing, or making tomato confit, sauce, ketchup, or tomato paste, you don't need much more than time and patience to preserve this beloved produce. Read on for our expert's tips on how to preserve tomatoes.

Canning Tomatoes 

At-home canning allows you to capture fruits and vegetables at the height of their flavor, and summer tomatoes are the perfect candidate for this process. While canning tomatoes may seem intimidating, all you need are sturdy jars, a large pot of water, and some heat-proof tongs to handle them. Canning tomatoes at home also means you know exactly what's going into your jars. With peak tomatoes, little more is needed to can them than the tomatoes themselves and some salt. 

Remove the skins from the tomatoes before canning. It's important to use new jars, as used jars might not seal properly upon processing. Once processed, home-canned tomatoes often last as long as a year if stored in a cool, dry, and dark space. 

Drying Tomatoes 

Dried tomatoes are small nuggets of rich, concentrated tomato flavor "that lend sweet, savory, sour, and umami notes as well as a burst of color so they can be considered truly timeless," says Olivia Roszkowski, the chef-instructor of plant-based culinary arts at the Institute of Culinary Education in New York City. "If not used correctly, however, the flavor can be quite overwhelming. It is important to soak them thoroughly so they integrate properly into your dish and allow you to process them into smaller pieces if applicable."

Follow Martha's recipe to dry tomatoes at home, and keep these tips in mind: 

• Start with good quality, ripe tomatoes: "This will translate to the flavor they lend when dried," says Roszkowski. 
• Dry tomatoes with a dehydrator or an oven on a low setting: “The lower the temperature when drying, the better—low heat will help preserve some of the delicate, volatile flavor molecules,” says Roszkowski.
• Spread out tomatoes and give them lots of space to encourage a quick and even drying process. 
• "Make sure the tomatoes are completely dehydrated and cool completely before storing to discourage mold growth," says Roszkowski. 
  

Tomato Confit 

To confit food means to submerge it in a bath of fat (such as duck fat or olive oil) and cook it at a low temperature for a long amount of time. "Confit" comes from the French word confire, literally "to preserve."

"The flavors that result are sweet, mellow, and cooperative for many uses," says Roszkowski, who also notes that confiting allows you to include additional flavors like woody herbs (rosemary, sage, and thyme) and even garlic to impart more flavor to the tomatoes.

Once confit tomatoes are complete, "it is best to strain the confit-ed tomatoes and store them separately (from the oil) to prevent anaerobic microbe growth like botulism," says Roszkowski. Saved the used oil for a variety of applications, such as dipping breads or making sauces or vinaigrettes—it can also be used to make future tomato confit. Both the confit tomatoes and the oil should be stored in the refrigerator.

Tomato Sauce 

Making tomato sauce is a simple way to preserve tomatoes. And having homemade tomato sauce on hand means you always have the makings for dinner. Roszkowski recommends the pressure cooker method for making tomato sauce. She says it infuses a large amount of flavor in little time. "In a matter of minutes, your tomato sauce will have a greater amount of depth and taste like you simmered it for hours," says Roszkowski. 

Another one of her secrets for a great tomato sauce is to toast some savory umami-rich fridge staples, like miso paste or even tomato paste (double tomato!), in olive oil over medium-low heat for an extra savory flavor and increased depth to your sauce.

Smooth, blended sauces keep well in the freezer and can even be stored in ice cube trays or similar smaller quantities rather than in large containers.

Tomato Paste and Ketchup 

These two methods of preserving tomatoes overlap since ketchup is made using tomato paste.

Tomato Paste

We're accustomed to buying tomato paste in a can or tube, but it's quite simple to make at home yourself. Tomato paste is pureed tomatoes that are cooked down for many hours at a low temperature on the stovetop or in the oven. It takes time and attention, as it's a process that requires a lot of stirring over several hours, but making homemade tomato paste is worth it. 

Once the tomato paste is done, store it in small jars and keep them as you would fresh canned tomatoes, or store the tomato paste in the fridge for several months. Make sure the surface of the paste is airtight. This can mean using a piece of plastic wrap pressed to the surface or covering it in a puddle of oil that gets replaced every time you scoop out some paste. 

Tomato Ketchup

Adding Worcestershire sauce, sugar, and spices to a thickened (but not quite pasty) tomato paste will yield a fabulous homemade ketchup. And is there anything you can't use it for? It'll be your go-to dip for fries, chicken fingers, mozzarella sticks, burgers, and more.

Freezing Tomatoes 

Storing whole tomatoes in a zip-top bag in the freezer may seem common, but it's an extremely effective and easy way of preserving tomatoes. It's unnecessary to peel them as frozen tomatoes are easier to peel than fresh. Score the bottoms with an "x" before freezing and eliminate as much air from the bag as possible. A food vacuum sealer is also a helpful tool for this job. Frozen tomatoes are ideal for cooking sauces but less so for making salads or adding to sandwiches.