Over 90% of what I use my microwave for (and with me, many others) is to reheat food. Only a small sliver of my microwave activity actually involves cooking food in it. And within that narrow realm of microwave cooking, there’s one food I cook in a microwave most often: the humble potato*.
Microwaving a potato has several great benefits. For one thing, the microwave slightly dries out a potato, making it easier to crisp it up later. The other: it cooks a potato incredibly fast. The reason it works so well? Microwaves just happen to be great at heating up water molecules, and a potato consists of a lot of water.
Microwaving peeled potatoes is a reasonably straightforward process. Start by cutting the peeled potatoes into 1/4-inch thick slices. Place the slices in a microwave-safe dish and add enough water to cover them. Cover the dish with a lid or plastic wrap, leaving one corner uncovered to allow steam to escape.
Cooking a potato: softening and browning/crisping
When you prepare a potato, there are generally two things you’re after:
- The potato should be cooked throughout and as a result the inside should be tender and easy to chew. This transformation is mostly a result of the cooking and gelatinization of starch within the potato.
- Optionally, you might also be after a crunchy or crispy piece of potato. Maybe, you’d also like it to turn a slight light brown color, for extra flavor? Browning occurs because of the Maillard reaction, a chemical reaction that needs enough heat. Crisping up happens once the outside of a potato turns sufficiently dry.
To achieve one or both of these goals, there are plenty of ways to go about. You can deep fry them, boil them in water, fry them in a pan, bake them in the oven, or use an air fryer. So when would you choose to use a microwave to cook the potato? Mostly to speed things up. And, more often than not, you’d still use one of the other methods after it’s been microwaved. Before (raw) After (cooked in the microwave)Potatoes before and after cooking in the microwave. Notice how the potatoes have dried out slightly, the skin has gotten wrinkly
A microwave can cook a potato fast. Depending on the size and quantity of your potatoes, you can cook a whole potato within 6 minutes or so, from start to finish. Compare that to baking them in the oven, which can easily take an hour, or boiling them in hot water, often taking over 15 minutes. This is because microwaves do not heat up potatoes in the same way an oven or a stovetop does. Whereas ovens heat up air, and stoves heat up pots and pans, microwaves use waves – appropriately called microwaves – to heat potatoes. Whereas conventional methods heat potatoes from the outside-in, microwaves cook the whole potato in one go.
To do so, microwaves consist of waves of a specific length and frequency that are great at ‘exciting’ water molecules. That is, their frequency is such that they can get water molecules moving very easily. When molecules move more and more quickly, they heat up, the temperature increases. Potatoes contain a lot of water, over 80% of the weight of a raw potato is water. As such, a microwave is great at heating up a potato, but only up to about 100°C (212°F), the boiling point of water.
By heating up the water, the starch in the potato will start to cook. It will absorb water and gelatinize, softening the potato as a whole and making it digestible. This process requires temperatures well below the boiling point of water, so can take place in a microwave without any issues.
That said, a microwave can’t create a crunchy, crispy potato, nor have it turn brown due. Both of these processes require temperatures above the boiling point of water. As a matter of fact, to turn a potato crispy you’ll need to evaporate significant amounts of water from the outside of a potato. The microwave is simply too humid and not hot enough, to do so. It’s why your potatoes will turn out cooked through perfectly, they won’t be brown, nor have a super crispy skin. Potatoes were cooked in the microwave and are now ready for the final bake in the oven to brown and crisp up.
Even though a microwave itself can’t create a crunchy potato, it can help you make a crunchy potato fast in a next step. This is because a potato pre-cooked in a microwave is relatively dry. You can cook potatoes in a microwave without adding any additional water. Just place them in the microwave and get going. This has a great advantage: potatoes don’t turn moister than they were to start with. If anything, they’ll dry out slightly. So compared to a potato pre-cooked in boiling water, or even steamed, it’s a lot drier. Compared to one cooked in the oven, it has a similar dryness, however, you got there a lot quicker.
Drying out the potato has a lot of advantages. During frying, you spend a lot of energy evaporating moisture. The moisture needs to be evaporated to get a crispy outside. If your potato starts with less water, you need to evaporate less. As such, it takes significantly less time to start crisping up and turning brown.
How to microwave potatoes
Microwaving potatoes is simple and doesn’t depend much on the type of potato you’re using:
- wash them;
- poke them – this helps steam escape through the skin and prevents little explosions of starch in your microwave;
- microwave them at max. wattage (eg. 900W).
If you feel comfortable trying it out, that’s all you need to know. But if you want some more guidance, or need some help troubleshooting, here’s a few things to watch out for.
To ensure even cooking, make sure to turn your potatoes over about midway during cooking. Generally speaking, the bottom of your potato cooks faster than the top. This is because microwaves aren’t always great at evenly heating up food. Some parts of the food may be very hot, whereas others are still cool. This is because of how the waves travel through the food. They can strengthen but also weaken one another, causing these temperature differences. Microwaves with a rotating platter tend to have less of an issue with this problem, but if yours doesn’t have one of those, definitely make sure to move your potatoes around.
Size matters. Bigger potatoes do take longer to cook than small ones. That said, the difference isn’t as big as it is when cooking them in boiling water. If sizes don’t differ that much, you can easily cook them all together. Potatoes don’t easily overcook in the microwave, so some variation isn’t an issue. If you have some very small and some very large potatoes, it’s best to take the small ones out once they’re cooked and leave the large ones in to cook a little longer. As a starting point use the cooking times mentioned below:
- Small potatoes (2-5 cm / 1-2 inches) tend to take anywhere from 3-6 minutes to cook
- Medium-sized potatoes (5-8 cm / 2-3 inches) tend to take 5-8 minutes to cook
- Large potatoes will take >8 minutes to cook
The more potatoes you add to a microwave, the longer it takes for the potatoes to cook. This may feel contradictory if you’re used to cooking potatoes in boiling water. Once the water is boiling, it takes the same amount of time for the potatoes to cook, whether you’re cooking 1 or 20. That is not the case for a microwave, again, due to those waves. The power of your microwave is fixed with a certain wattage. If you add twice as many potatoes, let’s say 20, instead of 10, it still has a similar amount of energy available to cook those potatoes. As a result, it takes longer. It won’t take twice as long necessarily, but keep in mind that if you’re cooking potatoes for a party, it will take a lot longer than just cooking them for a few people. Comparing potatoes microwaved with their skin left on (left) vs. a peeled potato (right). Notice how the outside of the peeled potato has become uneven. It was also a little chewy. However, you didn’t notice the difference once they’d been fried in a hot pan afterwards.
You can cook a potato in the microwave with and without the skin. Which method you choose mostly depends on your personal preference. If it definitely easier to remove the skin of a raw potato, than it is to remove it from a cooked one. So, if you’re not a skin fan, taking it off in advance will be easier. However, removing the skin does impact the result of microwaving.
The skin protects potatoes during storage and helps keep moisture within – this is why it’s best to poke a few holes in whole skin-on potatoes, to allow some excess steam to escape. A peeled potato dries out more quickly than a potato that still has its skin on. In the microwave, the same applies. A potato cooked skin-on will remain moister. If you’re planning to fry or bake the potatoes afterwards, you won’t truly notice the difference, but if you’re using the potatoes in let’s say a salad, they can become a little chewy.
Cutting a potato has the same effect as peeling a potato, you’re removing the protective layer. But, it’s even a little worse since you’re also increasing the overall surface area. Potatoes cut into smaller pieces do run the risk of drying out in the microwave. As such, it’s often best to cook the potatoes whole and cut them once they get out of the microwave. Pre-cooking potatoes to use as filling in
How To Bake a Potato in the Microwave
Can you cook a potato in the microwave without the skin?
You can cook a potato in the microwave with and without the skin. Which method you choose mostly depends on your personal preference. If it definitely easier to remove the skin of a raw potato, than it is to remove it from a cooked one. So, if you’re not a skin fan, taking it off in advance will be easier.
What advantages do sweet potatoes without skin have?
Sweet potatoes without skin have several advantages. Compared to white potatoes, they are lower on the glycemic index and therefore do not cause blood sugar spikes as quickly. They are also a good source of fiber, which can help to regulate digestion. Additionally, sweet potatoes without skin are a good source of vitamins and minerals, such as Vitamin A, potassium, and magnesium. Sweet potatoes with skin have some of the same advantages, but they have more fiber. It is important to note that both kinds of sweet potatoes are healthy choices and can be part of a well-balanced diet.
Can you cook potatoes in a microwave?
Make a baked potato in the microwave by poking holes in it with a fork and then microwaving it for 3 to 4 minutes on high. Roast potatoes in the microwave by covering cubed potatoes with plastic wrap in a microwave-safe dish and cooking on high for 5 to 10 minutes.
Are microwave potatoes safe?
Yes, microwave potatoes are generally safe as long as they are properly prepared and cooked. It is important to pierce the potato with a fork or knife and place it in a microwave-safe dish with a small amount of water to prevent it from exploding. Make sure to use the right cooking times and power levels to ensure the potato cooks evenly.