How do you preserve tomato slices?

Preserving tomato slices allows you to enjoy the flavor of fresh tomatoes year-round. With the right preservation methods, you can store tomato slices for several months while maintaining their texture, taste, and nutritional value. There are a few key ways to preserve tomato slices – refrigeration, freezing, canning, and drying.

Table of Contents

Quick Refrigeration

The quickest and easiest way to preserve fresh tomato slices is to refrigerate them. This allows the slices to stay fresh for up to 10 days. To refrigerate tomato slices:

Wash and dry the tomatoes well before slicing them. Cut them into 1/4 to 1/2 inch slices.

Lay the slices in a single layer on a plate or baking sheet lined with paper towels. Allow them to sit for 30 minutes to drain any excess liquid.
Transfer the drained slices to an airtight container or zip-top bag. Make sure the container is big enough to lay the slices flat in a single layer.
Store in the refrigerator. The slices will stay fresh for up to 10 days.

Refrigerating tomato slices stops enzyme activity that causes them to overripen. The cold temperature also prevents the growth of microbes that cause spoilage. Just be sure to consume the refrigerated slices within 10 days for best quality.

Freezing

Freezing is one of the simplest long-term preservation methods for tomato slices. With proper freezing techniques, the slices will retain their texture and taste for up to 12 months. Here’s how to freeze tomato slices:

Select ripe, flavorful tomatoes and wash thoroughly.

Slice the tomatoes about 1/4 to 1/2 inch thick. Lay them on a baking sheet in a single layer.
Freeze the slices on the baking sheet until completely hard and firm, about 2-3 hours.
Transfer the frozen slices to zip-top freezer bags or airtight containers. Squeeze out excess air before sealing.

Label with the date and return to the freezer immediately.
For best quality, use the frozen slices within 12 months.

The quick freezing process prevents large ice crystals from forming in the tomato flesh. This maintains the cell structure better so the slices don’t turn mushy when thawed. Blanching the slices before freezing can help further improve texture.

Blanching Before Freezing

An extra step of blanching tomatoes before freezing can help destroy enzymes and microbes that cause loss of flavor, color, and texture:

Prepare an ice bath by filling a large bowl with ice water. Bring a pot of water to a boil.
Boil the tomato slices for 30 to 60 seconds until slightly softened. Use a slotted spoon to immediately transfer them to the ice bath to stop the cooking process.

Once cooled, remove slices from the ice bath and pat dry. Proceed with the freezing method above.

Blanching isn’t necessary for freezing tomatoes, but it can help maximize their quality after long frozen storage.

Canning Tomato Slices

Canning is a popular way to preserve tomato slices with a shelf life of up to 18 months. The canning process uses high heat to destroy spoilage causing microorganisms and enzymes. Follow these steps for safe canning of tomato slices at home:

Wash and sterilize all canning jars, lids, and equipment. Tomatoes are a high-acid food with a pH below 4.6, so they can be safely processed in a water bath canner.
Wash tomatoes. Slice into 1/4 to 1/2 inch slices and pack into the clean jars. Leave 1 inch headspace.
In a large stockpot, bring enough water to a boil for the water bath canner. Simmer the packed jars in the canner for 40 minutes at 212°F.

Remove the jars from the canner using jar lifters. Allow to cool undisturbed for 12-24 hours.
Check the jar seals. Refrigerate any unsealed jars and consume quickly. Sealed jars can be stored in a cool, dark place for up to 18 months.

For an added safety precaution, the tomato slices can be acidified before canning. Add 2 tablespoons of bottled lemon juice or 1/2 teaspoon of citric acid per quart jar. Acidifying helps control the growth of botulism bacteria.

Choosing Tomatoes for Canning

Select only firm, perfectly ripe tomatoes for canning. Overripe tomatoes will turn mushy and underripe ones lack flavor. The best varieties for canning include:

Roma – Meaty flesh with few seeds
San Marzano – Excellent flavor and low acidity

Amish Paste – Firm, juicy flesh
Cherokee Purple – Good color and texture

Avoid heirloom varieties, which tend to have a softer flesh. For best results, can tomato slices within 6 hours of harvesting or purchasing.

Drying Tomatoes

Drying tomato slices through dehydration removes most of their moisture content, concentrating the flavors and preserving them long-term. Dried tomatoes can be enjoyed for up to one year. Here are two methods for drying tomato slices:

Oven Drying

Wash and slice tomatoes about 1/4 inch thick. Arrange in a single layer on baking racks set over sheet pans.
Place in oven set to lowest temperature (140°F-170°F). Prop the door open several inches to allow moisture to escape.

Dry for 6-8 hours, flipping slices halfway through. Tomatoes are done when leathery and brick red.
Pack dried slices into an airtight container. Store in a cool, dark place for up to 1 year.

Dehydrator Drying

Wash and slice tomatoes about 1/4 inch thick. Arrange in a single layer on dehydrator trays.

Dehydrate tomatoes at 135°F for 6-10 hours. Rotate the trays and check for doneness periodically.
Once dried, store the tomatoes in an airtight container in a cool, dark place for up to 1 year.

Drying concentrates the tomato flavor and caramelizes the natural sugars. Rehydrate dried tomatoes in water before use in recipes.

Pickling Tomato Slices

Pickling preserves tomato slices using salt brine or vinegar. It provides a tangy flavor and extended shelf life up to 12 months. Here’s how to pickle tomato slices:

Brine Method

Slice tomatoes about 1/4 inch thick. Pack tightly into sterilized jars.
In a saucepan, bring 1 cup water, 1 cup vinegar, and 1 tbsp salt to a boil. Pour the hot brine over the tomatoes leaving 1/2 inch headspace.

Cap the jars and let cool completely. Refrigerate for 1-2 days before consuming to allow flavors to develop.

Vinegar Method

Wash tomato slices and pack into jars as described above.
In the jars, layer slices with sliced onions, whole peppercorns, and fresh herbs like dill.

In a saucepan, bring 1 cup vinegar and 1 cup water to a boil. Pour over tomatoes leaving 1/2 inch headspace.
Cap jars and process in a water bath canner for 15 minutes. Store pickled slices up to 12 months.

Always use heat-treated vinegar for pickling. Only boil the brine, not the tomatoes themselves. Refrigerate jars after opening for long-term storage.

Storage Times for Preserved Tomato Slices

Preservation Method	Unopened Shelf Life	Refrigerated After Opening
Refrigeration	Up to 10 days	Up to 7-10 days
Freezing	Up to 12 months	Not applicable
Canning	12-18 months	Up to 5 days
Drying	Up to 1 year	Up to 1 year
Pickling	12 months	Up to 4-6 months

Always store preserved tomato slices in a cool, dark place for maximum shelf life. Refrigerate after opening for best quality and safety.

Choosing the Right Preservation Method

Deciding how to preserve your tomato slices depends on several factors:

Intended use – Refrigerating is best if using soon. Canning, pickling, and drying give longer shelf life.

Time commitment – Freezing is fastest. Canning and drying are more time-intensive.
Equipment needed – Canning requires specialized equipment. Freezing just needs airtight containers.
Texture and flavor – Canning retains the most fresh tomato flavor. Drying intensifies flavor while softening texture.

Once you understand the pros and cons of each preservation method, you can decide which technique works best for your needs and preferences.

Using Preserved Tomato Slices

Preserved tomato slices are versatile ingredients that can be used in many dishes. Here are some ways to use up your refrigerator, frozen, canned, dried, or pickled tomato slices:

Sandwiches and burgers – Top grilled cheese, BLTs, turkey sandwiches, or burgers with slices

Salads – Toss into fresh green, pasta, grain, or veggie-based salads
Pizzas – Scatter slices over homemade or store-bought pizza
Antipasto – Add to antipasto platters with meats, cheeses, and olives

Casseroles and bakes – Mix into egg bakes, lasagnas, pasta casseroles, and bread puddings
Sides – Saute into veggie side dishes or grain bowls
Snacks – Enjoy straight from the jar for a healthy high-fiber snack

Salsas – Chop and mix into fresh tomato salsa

Dried and pickled tomato slices tend to have a more concentrated, acidic flavor. Balance out their taste by pairing with creamy, hearty, or naturally sweet ingredients.

Troubleshooting Preserved Tomato Slices

With careful preservation methods, tomato slices will retain optimum freshness, texture, and taste. However, sometimes problems can occur:

Mold Growth

If white or colorful mold appears on refrigerated or canned tomato slices, it means the product was contaminated and should be discarded. Prevent mold by:

Sanitizing all equipment before use
Ensuring tomatoes are dry before storage

Processing jars for the full recommended time in a water bath canner
Checking seals on cooled canned jars before storage

Fermentation

If bubbles, cloudiness, or sliminess develop in refrigerated or brine-pickled slices, harmful fermentation is occurring. Prevent fermentation by:

Using vinegar with at least 5% acidity for pickling
Ensuring tomatoes are fully submerged in brine with no air pockets
Boiling brine before pouring over tomatoes

Texture Changes

Different preservation methods impact tomato texture:

Mushy canned tomatoes – Overprocessing causes too much heat exposure. Process jars for the recommended time.
Mushy frozen tomatoes – Storing at too warm a temperature or slow freezing causes cell damage. Quick-freeze slices.

Tough dried tomatoes – Drying at too high a heat. Use lower dehydrator/oven temperatures.

Monitor time, temperature, and preparation carefully to prevent undesirable texture changes in preserved tomatoes.

Discoloration

Over time, tomato slices may darken from bright red to an orange-brown hue. This is due to oxidation and the degradation of carotenoids. Prevent discoloration by:

Blanching slices prior to other preservation
Coating slices in olive or vegetable oil before freezing or drying
Storing slices in dark environments away from light

Consuming slices promptly once jars are opened

While harmless, discoloration impacts the appearance of preserved tomato slices. Take steps to maintain their vibrant red color.

Conclusion

With the right preservation techniques, you can enjoy fresh tomato flavor well past the short summer season. Refrigerating, freezing, canning, pickling, and drying all allow you to store sliced tomatoes for several months or up to a year. Each method has pros, cons and ideal uses. Pick the technique that best fits your time, equipment, and intended use. Follow proper preparation methods to maximize tomato safety and quality. With delicious preserved tomato slices, you can recreate the taste of summer in your winter meals and snacks.