corn on the cob – Food Science Institute

Boiling, microwave, Instant Pot. Which is best?

There isn’t much to cooking corn on the cob: you just shuck each ear, maybe cut off some of the stem, peel off the corn silks and drop them into boiling, salted water, and cook for 5 minutes. That’s it. The water should be salted enough that it smells like the ocean, and it is easiest to use kosher salt to achieve this. Serve with butter and salt on the side.

What’s wrong with this? Nothing except you might need a big pot for a large crowd. And, of course, you are steaming up your kitchen.

But some people rave about using the microwave or the Instant Pot for cooking corn, so we compared all three methods.

Microwaved corn

Some people claim that the microwave does the best job and you don’t have to heat up the kitchen with a pot of boiling water, so we tried this.

We cut the base off an ear of corn, but left the husk on, and using our best Internet research, microwaved the corn for 4 minutes. Taking a hot ear of corn out of the microwave requires hot pads and some care, and removing the hot, steaming husks is a challenge. And, all the silks come off smoothly, unlike the other methods.

The disadvantage again, is one of scale: you can only microwave a few ears at a time and removing the steaming hot husks from a bunch of them is best done with gloves or oven mitts. And, frankly, the corn tastes awful! (more below)

In the Instant Pot

Lots of people are enthusiastic about corn on the cob cooked in an Instant Pot. You have to shuck the corn as usual and pull of most of the silks by hand, but you can probably get 4-6 or more ears in an Instant Pot at once. We recommend putting the ears on the little trivet so they don’t stick to the pot. Add a cup of water and cook the ears for 3 minutes. Of course, by the time the water in the pot comes to a boil, this actually takes at least as long as boiling the water on the stove would, but you can cook a lot of ears quickly, and you don’t have to deal with scalding yourself on the husks.

How do they compare?

Cooking the ears in a pot of water tastes the best.
Ears cooked for 4 minutes in an 1100 watt microwave are hot and hard to handle, because the cobs are very hot, too. Further the corn takes on a bitter, cobby taste from the cob being heated. Actually they are really terrible.
We repeated the experiment, cooking the corn for only 3 minutes and this removed some (but not all) of the bitter aftertaste.
Our best corn came from cooking for 4 minutes at 50% power, where the bitterness is least apparent.

Surprisingly the corn cooked in the Instant Pot was little better.

Pressure cooking the corn for 3 minutes also cooks the cob, and some of that bitter aftertaste was present in the Instant Pot corn.
So, we repeated the corn cooking at low pressure instead of high pressure, which removed nearly all of that bitterness. But 3 minutes was not nearly enough. Six minutes at low pressure seems better. Quick Release either way.

Best results

5 minutes in boiling, salted water
4 minutes at 50% power in an 1100 watt microwave
6 minutes at low pressure in an Instant Pot

Some recipes suggest adding sugar and butter to the water in the Instant Pot. This probably doesn’t do much, because the water doesn’t touch the corn, and sugar is not volatile.

We found that spreading solid butter on the hot corn gives the bets flavor. Butter is an emulsion and melted butter usually leaves out the aqueous part.

Sometimes the simplest things get complicated. How best to cook corn on the cob? The goal is to end up with hot, butterable corn on a cob you can pick up and eat. Maybe wearing a bib!

We tried three different techniques for cooking corn on the cob: boil water, steaming in an Instant Pot, and cooking in a microwave. There are some advantages to each method.

Boiling

Far and away the simplest approach is to get a pot of water boiling and drop the shucked corn into it for 5 minutes, lift it out with tongs and serve right away. The advantage is scale: in a big pot, you can cook a lot of corn in a hurry.

Now some die-hards like to spread butter on the hot corn, and while this is entertaining, it is way better to just brush some melted butter on each piece before serving. We melted our butter in a small pitcher in the microwave, at 50% power to prevent the milk components from boiling.

Instant Pot

Another popular method for members of the Instant Pot owners cult is to put several shucked corn ears in the Instant pot with a cup of water under the trivet. Then, set the pot to steam under low pressure conditions. We found that 3 minutes in the put made pretty nice corn. The disadvantage is that it takes the pot more than 5 minutes to get that water to a boil and you can only do a few ears at a time in the pot: maybe 4 or so. In our experiment, we used the Quick Release after 3 minutes, rather than letting it cool down in the pot and perhaps overcook.

The corn comes out very well, but you have to clean out the pot when the boiling water pot is simpler to clean.

Microwave

The third approach is to put the ears in a microwave oven. In this case, you don’t shuck off the husk until afterwards, to keep the steam inside the ear. You cook them for 4 minutes, then cut off the bottom and pull out the corn. This did not work very well for us. Neither of out two trials resulted in “quick release” corn. We had to peel it manually, and when the husk, the corn and the cob itself are very hot, this is very tricky. Further, you really can only do 1-2 ears at a time, reducing scalability.

Results

All three methods produced tasty hot corn: we took a few bites from each and found no obvious differences. However, the microwaved corn is hot through and through, making it difficult to pick up the corn and eat it without burning your fingers. While we tried to pick corn ears that were similar in size, we didn’t succeed: the middle, smallest ear was microwaved, the left one cooked in boiling water and the right one in the Instant Pot.

However, as the corn cooled, we noted that the kernels of the microwaved corn began to collapse and pucker. We repeated this with another ear and found the same result. The water was evidently forced out of the kernels by the microwave heating, and when the corn cooled it was unsightly. While we didn’t notice a flavor difference, the difference in appearance indicates that the microwaved corn could be or seem to be less flavorful. Because of the difficulty in peeling the husks and the puckered kernels, we ranked this technique third, and don’t recommend it.

Among the other two: the boiled and the Instant Pot are about the same, but the open pot of boiling water lets you make far more corn in a hurry for a crowd. We would guess that you could only do about 4 ears at a time in the Instant Pot, and the elapsed time is greater, because once the open pot of water is boiling, you can cook all the corn you want without a reheating step.

We omitted cooking corn on a barbecue grill because the results are so different, but you can, if careful, caramelize the kernels a bit to make very good corn without steaming or boiling.

Food Science Institute

The best way to cook corn on the cob!