How to Store Sun-Dried Tomatoes Long Term (For Years)

Sun-dried tomatoes are one of those ingredients that punch well above their weight in the kitchen, intense flavour, long shelf life, and endlessly versatile.

But store them wrong and they mold, go rancid, or in the worst case create conditions for botulism growth.

Store them right and they last anywhere from a few months to two decades, depending on the method.

Here is every proven storage method, when each one is appropriate, and the one safety rule you cannot skip.

The Safety Rule Before Anything Else

Before the methods: never store sun-dried tomatoes packed in oil at room temperature unless they were commercially prepared and sealed.

Any moisture in the tomatoes combined with oil creates conditions where botulism can grow in an oxygen-free environment at room temperature. Botulism is odourless and tasteless, so you won't know until it's too late. Oil-packed tomatoes belong in the fridge, always.

How Long Do Sun-Dried Tomatoes Last?

Shelf life depends entirely on how dry the tomatoes are and how they're stored:

Storage method	Shelf life
Room temperature, airtight jar (fully dry)	6 to 12 months
Refrigerator, airtight container	Up to 12 months
Freezer, airtight bag	12 to 18 months
Oil-packed, refrigerated	2 to 3 months after opening
Mylar bag + oxygen absorber (fully dehydrated)	Up to 20 years
Tomato powder in Mylar bag	Up to 20 to 25 years

The jump from 12 months to 20 years between pantry storage and Mylar comes down to one thing: oxygen and light elimination.

A jar in a dark pantry slows spoilage. A sealed Mylar bag with an oxygen absorber essentially pauses it.

How to Know If Your Tomatoes Are Dry Enough

This is the step that decides whether long-term storage works or fails. Tomatoes that aren't fully dry will mold even inside a sealed bag. Two reliable checks:

The snap test

A fully dried tomato piece should be leathery and pliable but not sticky or soft. If it bends and snaps cleanly at the edges, it's ready.

If it feels moist or leaves residue on your fingers, it needs more time in the dehydrator.

The weight test

Moisture loss should reach at least 75 percent of the original weight.

For example, 500 grams of fresh Roma tomatoes should yield 100 to 125 grams of dried product. Weigh before and after drying to confirm.

The conditioning step

Even tomatoes that pass the snap test can have uneven moisture distribution. After drying, place them in a loosely closed jar for seven to ten days, shaking daily to distribute any residual moisture.

If condensation appears on the inside of the jar, return them to the dehydrator. This step catches hidden moisture that could ruin a sealed Mylar bag months later.

Only tomatoes that pass all three checks are ready for long-term Mylar storage.

How to Store Sun-Dried Tomatoes in Mylar Bags

Once your tomatoes are confirmed dry, the process mirrors what you'd use for any other dehydrated food.

The difference is that tomatoes have high acidity and can hold residual moisture more stubbornly than grains, which makes the dryness check above non-negotiable.

1. Let them cool completely after dehydrating, at least 30 minutes at room temperature uncovered. Sealing warm tomatoes traps condensation.
2. Portion by how you'll use them. A quart Mylar bag holds a meal-sized portion that you open and finish. A 1-gallon bag holds a larger batch for a household that uses them often. Don't pack a bag so large that you expose the whole supply every time you open it.
3. Add an oxygen absorber. Use 300cc for a quart-size bag. The absorber removes residual oxygen and keeps the environment stable for the long haul.
4. Heat-seal the top in one straight line across the full width, sealing high so you can cut it open later and reseal with the zipper. For the full sealing method see our guide on how to seal Mylar bags.
5. Label with contents and date. Sun-dried tomatoes are unrecognisable in a sealed opaque bag after a year.
6. Store in a cool, dark place below 70°F. A food-grade bucket adds rodent and puncture protection.

The Better Long-Term Option

If your tomatoes are fully dehydrated, grinding them to powder before sealing is actually the smarter long-term move.

Powder has almost zero residual moisture risk, which means it's safer to seal and lasts longer than whole pieces.

The flavour is concentrated and the powder rehydrates easily into sauce, soup base, or seasoning.

Process fully dried tomatoes in a coffee grinder or food processor until fine, let the dust settle before opening the grinder, then seal in a quart bag with a 300cc oxygen absorber. Tomato powder stored this way lasts 20 to 25 years and takes up half the space.

Other Storage Methods Worth Knowing

Refrigerator

The easiest option for tomatoes you'll use within a year. Place fully dry tomatoes in an airtight container and refrigerate. They keep their colour and flavour well and require no special equipment.

Freezer

Best for tomatoes with any doubt about moisture level. Freeze in a single layer first, then transfer to a sealed bag. They keep for 12 to 18 months and are safe regardless of moisture content because freezing inhibits mold and bacteria.

Oil-packed, refrigerated

Layer dry tomatoes in a clean jar, cover with good olive oil, and refrigerate. They keep for two to three months after opening and the oil takes on the tomato flavour for cooking. Refrigerate from day one and never leave at room temperature.

For a broader look at which foods store well long-term and which don't, our guide on foods to store in Mylar bags covers the full list alongside the moisture rules that determine shelf life.

Common Mistakes to Avoid

• Sealing tomatoes that aren't fully dry. The number one failure. Always condition first.
• Storing oil-packed tomatoes at room temperature. A genuine botulism risk. Always refrigerate.
• Using too large a bag. Every opening exposes the whole batch to air. Portion to what you'll finish.
• Skipping the oxygen absorber. Tomatoes are acidic and their oils oxidise. The absorber is not optional for long-term storage.
• Adding herbs or garlic to oil-packed jars without acidifying. Fresh additions introduce moisture and raise botulism risk. Use dried herbs only, or acidify with white wine vinegar before adding anything.

For the complete list of what trips people up with Mylar storage across every food, see our guide on mistakes to avoid when using Mylar bags.

Final Verdict

Dry-packed sun-dried tomatoes last up to 20 years in a sealed Mylar bag with an oxygen absorber, but only if the tomatoes are fully dehydrated first.

Confirm dryness with the snap test, weight test, and the seven-day conditioning step before sealing anything long-term. Oil-packed versions stay in the fridge, always, with no exceptions.

When you're ready to seal your supply, Roylo Globe carries Mylar bags and oxygen absorber kits in every size with labels and clips included, so you have everything you need to store your tomatoes the right way.

Frequently Asked Questions

Can you store sun-dried tomatoes in Mylar bags?

Yes, but only if they're fully dehydrated with no oil. Dry-packed, oil-free sun-dried tomatoes sealed in a Mylar bag with an oxygen absorber last up to 20 years. Oil-packed versions must be refrigerated and cannot go in Mylar.

How long do sun-dried tomatoes last in Mylar bags?

Fully dehydrated, oil-free sun-dried tomatoes last up to 20 years sealed with an oxygen absorber in cool, dark storage. Tomato powder lasts even longer, up to 25 years.

Why can't you store oil-packed sun-dried tomatoes at room temperature?

Oil combined with any residual moisture creates conditions where botulism can grow in an oxygen-free environment at room temperature. Botulism is odourless and tasteless. Oil-packed tomatoes must be refrigerated at all times.

How do you know if sun-dried tomatoes are dry enough for Mylar storage?

They should pass three checks: the snap test (leathery but not sticky), the weight test (at least 75 percent moisture loss), and the seven-day conditioning step to catch uneven moisture before sealing.

Can you freeze sun-dried tomatoes instead?

Yes. Freezing works well for any batch you're not confident is fully dry, since the cold prevents mold and bacteria regardless of moisture content. They keep 12 to 18 months in a sealed freezer bag.