What Are Sun-Dried Tomatoes? | Concentrated Flavor, How They’re Made

One bite of a sun-dried tomato delivers a flavor punch that fresh tomatoes can’t match — concentrated sweetness, tartness, and a deep savory richness. They are a staple in Mediterranean cooking and American kitchens alike, prized for transforming a simple pasta, salad, or sandwich into something memorably bold. The key is understanding how they’re made, the different drying methods available, and how to store them safely once you’ve made or bought them. Here’s what you need to know.

How Sun-Dried Tomatoes Are Made: The Traditional Process

Commercial and traditional sun-drying follows a straightforward sequence. Peak-season Roma or plum tomatoes are washed, halved lengthwise, and most of the juice and seeds are squeezed out. A light sprinkle of salt draws out additional moisture, and some commercial producers use sulfur dioxide to preserve the tomatoes’ red color. The cut halves are placed cut-side up on parchment-lined trays or wire racks, covered with mesh to block insects and dust, then set in direct sunlight for four to ten days — typically four to seven depending on the weather and slice thickness. The tomatoes are turned occasionally for even drying and brought indoors overnight to prevent condensation, which can slow the process and risk mold.

The result is a tomato that is dry, firm, and pliable — slightly crunchy when bitten, but not brittle. Over-drying until brittle reduces their usefulness, so the ideal texture is similar to dried fruit: chewy and stretchy.

Alternative Drying Methods (When the Sun Isn’t an Option)

Living in a cloudy climate or just want faster results? These oven and appliance methods simulate sun-drying closely:

• Oven method: Set to 240°F (115°C) and dry for 4–6 hours on parchment-lined sheets.
• Air fryer method: Set to 240°F and dry for 60–90 minutes.
• Dehydrator method: Set between 135°F and 160°F (57–71°C); drying takes 8–10 hours, though some sources recommend up to 48 hours for certain setups.
• Low-heat oven (cloudy day option): Set to 120–140°F (50–60°C) to gently simulate sun conditions over a longer period.

All methods share the same completion test: the tomatoes should feel dry and firm on the outside but remain pliable — not brittle. For anyone ready to start with the best store-bought options, our tested roundup of the best dried tomatoes for cooking covers what to look for in quality and flavor.

Storage and Shelf Life: Keeping Them Fresh

How you store sun-dried tomatoes depends on their moisture level and whether they’re homemade or commercial. Dry tomatoes kept in an airtight jar or container in a cool, dark pantry — adding dry rice grains or a food-safe desiccant — will last for months. Refrigerated dry tomatoes keep for two to three weeks; frozen, they last several months. Commercial oil-packed varieties are safe due to industrial processing.

Avoiding moisture retention is critical: tomatoes that haven’t lost at least 90% of their moisture will spoil quickly unless stored in olive oil. Semi-dried tomatoes dried for only three days should always be kept in oil in the refrigerator.

Nutrition and What to Look For

Sun-dried tomatoes retain high levels of lycopene, antioxidants, and vitamin C despite the moisture loss — their nutrients become more concentrated along with their flavor. The color darkens significantly during drying, and salt or sulfur dioxide pretreatment helps maintain a more vibrant red. Individuals with sulfite sensitivity should check labels on commercial products, as some use sulfur dioxide for color preservation. The most common commercial variety is Roma, grown extensively in Turkey — a major global producer.

One clarification: despite the similar name, “SunSugar” or “Sun Gold” tomatoes are fresh hybrid cherry varieties with golden-orange color — they are not sun-dried. The term “sun-dried” strictly means the fruit has been dried by the heat of the sun, not a specific tomato variety.