The Reason You Shouldn't Reheat Tomato Sauce In The Microwave

Microwave ovens are everywhere, and an estimated 90% of American homes have one, according to Popular Mechanics. Perhaps surprisingly, microwave ovens have been used to cook things since 1946. Commercially available models in the mid-1940s, called Radarange, were six feet tall, weighed more than a third of a ton, and cost a whopping $5,000 at the time, which would be over $50,000 in 2022, says the American Physical Society. Now, microwave ovens cook everything from pizza and popcorn to pasta and pecan pie. They're appliances of convenience that obviate preheating an oven and getting pots and pans out for the stovetop.

However, there are some things you probably shouldn't put in the microwave. No matter how hard you try, some items just don't work well. The key to microwave ovens cooking your food comes from water, notes the FDA. Microwaves interact with water molecules, causing them to heat up rapidly and eventually come to a boil. Heat up something too much, and your foods could dry out completely, says Wonder How To. However, foods with high water content heat up quickly, which can be a problem for liquid-based foods, including tomato sauce.

Tomatoes themselves are about 94% water, via Tyrant Farms, so it's no wonder that tomato sauce heats up rapidly in a microwave. However, unlike water which would boil and evaporate into steam, tomato sauce has a thicker and stickier consistency. Real Simple states the steam builds up into bubbles under the top level of the sauce. Stirring the sauce after you heat it could actually cause a miniature volcano to erupt all over your microwave.

If you don't stir it, the tomato sauce may end up creating red dots all over the inside of your appliance from the airborne bits of tomato, vegetable oil, and spices. Then you have to clean up the mess on your microwave walls before the sauce dries out even further, leaving you to scrape it off. And you should also watch out for splatters on your clothes, causing stains that may not come out unless you wash them quickly, notes the Cleaning Institute. Plus, there's the dreaded act of scraping the crust of overly-dried sauce from the inside of your perfectly good pasta bowl.

Other tomato-based products, like ketchup, have similar difficulties in the microwave. But there are ways around this. The first move you should make is to revert to the traditional way of heating up food in the kitchen: your cooktop. Real Simple notes you should warm up any sauces, not just tomato-based ones, in the smallest saucepan you have. This allows you to set the temperature and stir the sauce without removing the tomato sauce from the heat source. You can also cover it with a lid. Heating sauces on a stove gives you more control over the heating process.

Food Network has some tips for heating foods in the microwave, including sauces, if you still want to go that route. The site recommends setting the timer on your microwave for half-minute intervals on higher settings. Microwave Meal Prep suggests half a minute on half power for sauces and stirring the sauce after each time interval. One more tip is to cover the bowl with a damp, clean towel (which helps your sauce heat up more evenly), parchment paper, or microwave-safe plastic wrap to prevent splatters. Heating up tomato sauce doesn't have to ruin your dinner. Just follow these simple tricks to elevate your microwave game and save yourself some cleanup.