Is Sun-Cooked Tomato Sauce Safe?

You've likely heard the expression, on a super-warm day, that it's hot enough to cook an egg on the sidewalk. However, sticking to your pan in the kitchen is probably a safer option when it comes to egg cookery.

But, it could be time to add this sun-cooked tomato sauce to your list of ways to use tomatoes in the summertime. A viral TikTok video has users divided over how safe it is to use the sun to cook. Here's everything you need to know about what sun-cooked tomato sauce is and how safe it is to eat.

Related: 18 of Our Juiciest Tomato Recipes for Summer

Babs, the popular one-name TikTok user @brunchwithbabs, shares food and life hacks on her platform to nearly 2 million followers. She suggests giving her "sun pasta" a try in the summer.

Babs' recipe includes diced tomatoes, parsley, basil, lemon juice, olive oil, garlic, salt and pepper. The ingredients are combined in a bowl, covered with plastic wrap and set out in the sun for five hours. The end product, which somewhat resembled bruschetta, was served on cooked pasta (cooked indoors, not outside). But some commenters seemed less concerned with the flavor of the sauce, and more worried about the potential safety risk of cooking in the sun.

Technically, yes. You can use a solar oven or solar cooker to effectively cook using the sun's rays. These pieces of equipment (available at your local camping supply store) concentrate sunlight on a small area, but the process only works well if it is hot outside and there's direct sunlight. Typically made with aluminum or silver, the reflective panels of the cooker are curved so the sunshine hits the top and is reflected downward onto the food. (Try these camping-friendly recipes for your next outdoor excursion, no solar cooker needed.)

While it is possible to cook food using the sun, it might not be the safest option. Think of the radiant heat used to cook over grills or under broilers, says the Institute of Culinary Education's director of nutrition Celine Beitchman. It's not putting your food in direct contact with fire, but it is cooked indirectly, and it takes time to cook depending on the heat source and object you're trying to cook. "With animal-sourced foods and some plant foods that have a higher risk for spoilage, you want to be extra cautious about timing, so you don't grow harmful microbes or spread them to other foods," she says. "You also want to consider who's going to eat the finished product. Some people, like the elderly and immunocompromised, are more vulnerable to foodborne illness," which can be passed via tomatoes.

According to the USDA's Food Safety and Inspection Service, hot foods should be held at a temperature above 140℉, and cold foods should be kept below 40℉. Anything in between is considered to be in the "Danger Zone" where temperatures allow for bacteria growth that could potentially be harmful to humans. FSIS also recommends not leaving food in the Danger Zone for more than two hours—one hour if the ambient temperature is above 90℉. Babs doesn't mention ambient or food temperatures in her video.

The exact origins of this sauce are unclear, but some commenters on TikTok had already tried this recipe at one point, labeling it "raw sauce" or "summer sauce." While another commented below Babs' video on Instagram that Chicago may be a potential point of origin for the sauce. A recipe dating back to 2010 published via user submission on a popular food website featured a similar recipe with tomatoes, fresh basil, olive oil and salt "cooked" together in the sun.

Don't confuse sun-cooked with sun-dried. We have sun-drying (which reduces the amount of water content in food to varying degrees, aka dehydration) to thank for the way certain foods are made, Beitchman says: "That's how sun-dried tomatoes, dried mushrooms and jerkies might be produced on a small scale. It's how rice paper is made in parts of rural Vietnam, and how fruits like mangoes are dried across parts of the Americas. Sun-drying is also used to make white pepper, vanilla pods and black tea."

While using the sun as a heat source to cook is a perfectly legitimate way to prepare different foods, use caution. Be aware of the temperature Danger Zone and consider who you're cooking for before you decide to rely on the sun for heat.

If you want to try something new with your tomatoes at their peak, try slow-roasting them instead of using the sun. Or, look for new heirloom tomatoes to get you out of your usual routine.

Related: 6 Tasty Things to Try with All of Your Green Tomatoes