Microwaves are a quick and convenient way to heat our food, but sometimes they can make it soggy. If you’ve ever had a really great meal, but then when you put the leftovers in the microwave to heat them up, it turned into a soggy mess, you’ve probably wondered why.
Why do microwaves make food soggy? The electromagnetic radiation used to heat food causes water molecules in the food to move. The friction from that movement causes the heat that warms the food or liquid in the microwave. Because the moisture cannot leave the microwave, it remains in the food, causing it to become soggy.
Microwaves are an important part of most of our kitchens. We use them daily, but rarely give them much thought, so we may as well know a little more about the way they heat our food. We’re going to discover exactly what makes the water wiggle and ways to reduce soggy food.
The Science Behind It
Microwaves heat our food using electromagnetic radiation. You may remember a little bit about this from your high school science class. The form of electromagnetic radiation that microwaves use is called, not surprisingly, microwaves.
Microwaves are one type of wave on the electromagnetic spectrum, which also includes radio waves, infrared light rays, visible light waves, ultraviolet light waves, x-rays, and gamma rays. Microwaves can be found between radio waves and infrared waves on the electromagnetic spectrum. The frequency that is used for most microwave ovens is 2,450 megahertz (or MHz).
Electromagnetic radiation consists of both electric and magnetic fields that are oscillating perpendicular to each other. Their magnitude and direction are changing each second.
The heating process works like this:
- When you turn on your microwave, a vacuum tube called a magnetron uses the electrical energy to transmit the microwaves through a waveguide to the heating chamber.
- That energy then causes the water molecules in the food to vibrate. Water molecules are positively charged at one end and negatively charged at the other. The two ends rock back and forth in order to align with the electric waves in the electromagnetic energy being produced.
- The friction created by this process creates heat in the heating chamber, and this heat is absorbed by water molecules in the food, thus heating the food.
And with nowhere for the moisture that this creates to escape to, we can end up with soggy food.
This doesn’t happen when we cook food in an oven because ovens use a different process that heats the food from the outside and then transfers that heat to the inside of the food.
This allows the outside of the food to stay crispy. But since microwaves are bouncing around the heating chamber of a microwave oven and heating all food at the same time, it’s harder for food to remain crispy.
There is a common belief that microwaves heat food from the inside out, which is the opposite of an oven, which heats from the outside in. While that’s true of an oven, a better way to describe how a microwave heats food is that it heats all parts of the food at the same time. However, as you’ll see in one of the tips down below, it is not a completely even heat.
Tips for Making Food Less Soggy
So now that we know why microwaves make our food soggy, there are some tips and tricks that we can use to make it less soggy.
- When you’re reheating a slice of pizza, put a small, microwave-safe mug or dish filled with water next to the pizza in the microwave. This extra water will absorb some of the microwaves that normally would have gone directly to the pizza, thus decreasing the amount of moisture in the pizza. Be sure not to heat the food for too long.
You don’t want the water to come to a boil, or it will release water vapors, which will defeat the purpose. For a technical explanation of how this works, check out this article. You’ll be able to tell your friends all about “dielectric constants of water.”
Pro Tip: While you don’t want the water to boil when you’re heating pizza, boiling
water is a good way to clean the inside of your microwave. Just boil some water with
lemon slices in it and let it sit for a few minutes with the microwave door closed. This will
make cleaning a breeze.
- Place a paper towel or a piece of parchment paper underneath your food. This will absorb some of the excess moisture and keep it out of the food.
- Always pay attention to the cooking time. Foods that have a higher water content will generally cook more quickly because the higher water content will absorb the heat faster than a food that has less water content.
- If your plate is small enough, don’t place it directly in the center of the microwave. Set it slightly off to the side. Or if your plate is too big to do this, try to arrange the food on the outside of the plate. The heating chamber does not heat every area evenly, and the center of the microwave is often a colder spot, so this will help your food to heat more evenly.
In a nutshell, the way to make your food less soggy is to take factors such as the water content of the food and the cooking time into consideration.
Microwaving Different Types Of Food
You will obviously get different results with different types of food. If you’re reheating a slice of pizza, it’s more likely to get soggy. If you’re reheating pasta, it’s more likely to dry out. So it’s important to take into consideration what type of food you’re dealing with. When you’re using a microwave, sometimes there’s a very fine line between too soggy and too dried out.
If you want to microwave different types of food at the same time, you might be better off doing them separately so that you can heat each one the way it should be heated. And be sure to take into consideration the power of your microwave when determining the appropriate cooking times.
And there are always some foods that will taste better if you heat them in the oven. For example, leftover french fries are one food that is very hard to microwave with good results. You’re better off heating them in the oven if you can. Or better yet, eat them while they’re still hot, and they don’t require reheating of any kind. This is especially true if you like them extra crispy.
Like many of our greatest inventions, microwaves were discovered by accident. In 1945 an engineer who was working with radar realized that the microwaves had melted a candy bar in his pocket. From that random discovery, the idea for the microwave oven was conceived.
Final Thoughts
Microwaves are a great way to cook or reheat your food. They are a convenient option when we need a quick meal on the go, or just need to reheat some leftovers in a hurry. However, what we gain in convenience, we sometimes lose with the quality of our food.
But there are some steps that we can take to help with that. So these are all things that you can keep in mind the next time you go to reheat your leftover slice of pizza and wonder why it came out so soggy.