Microwave Tricks: Ungrilling Corn on the Cob

The last time I wrote about buying fresh corn more or less in season, my daughter was seven years old, green of hand and shin from a day camp project, and eager for me to do the handling so she could inspect each ear without touching them herself or turning them green. Now she’s a camp counselor at a nature center and almost done with college. So it’s been a while.

I wouldn’t normally think I had much to say about corn on the cob–I like it in a limited way, and actually I prefer to use the kernels for microwave chiles rellenos, but my husband and daughter both go for it, so usually when the price has finally dropped under 50 cents an ear (signalling “corn season” prices in the LA area) I buy it mostly for them, and I cook it as simply and quickly as possible, steaming it in the microwave. Because no matter what else may be true, when there’s corn in LA, it’s pretty hot out and the last thing I want to do is heat up my little galley kitchen.

Which turns out to be the deciding factor for this post. Temperatures around the southwest are edging up over 100–as expected; but at this point the northeast has also been in the 90s, and Portland, Oregon, has hit 116, hot enough to cook mussels in the harbor. It’s insane.

But microwaving corn isn’t just a survival tactic or a contingency plan.

My daughter was recently home for two weeks before going back to New York and lamented that my corn is “so much better” and tastes fresher than most of her friends and my in-laws make it. My in-laws are all hands-on denizens of Northern Califoodia, and a typical Fourth of July weekend sees barbecueing with many homemade sauces and bastes and corn roasted in the husk and so on.

So I was surprised–pleased, because my daughter has a better palate than I do, and she tends toward snark around me. But surprised, because she apparently meant it. Not being a huge corn fanatic, I think, “it’s just corn in the microwave, big deal.” Certainly, microwaving is much less glamorous and won’t result in attractive grill marks on the corn, much less the irreplaceable smokiness. So why would it be better?

My husband grew up for a while in Southern Illinois, corn country, and says the best corn he ever ate was when his family visited friends on a local farm. The hosts brought a stockpot of water out to the field between rows, set it boiling on a brazier, and instead of picking the corn, they just bent the nearest stalks directly into the pot for a few minutes, just enough so that the ears in the pot were cooked through and juicy, not enough to let them overcook with shriveled kernels or turn sicky-sweet and starchy like canned corn.

So that’s the ideal, rustic way to make perfect, exquisitely fresh corn on the cob. Ironically, a microwave can get you fairly close with supermarket corn that is obviously not still growing on the stalk for ultimate freshness, and you don’t have to visit southern Illinois farm country in the middle of the summer (which I have done, once, and it was really, really hot and stifling in my uncle’s childhood home). Or schlep pots of water out to the field in the middle of said summer and wait for them to boil.

Microwave-steaming is very different from stovetop methods like boiling, blanching or steaming. It’s not just the way it heats food–acting preferentially on the water molecules in or around the food–but how the food comes out as a result. If you do it right–just a little water, not a swamp, and put a lid on the container–a few minutes on high power will steam things like broccoli or asparagus to fork-tender while preserving the bright jewel green color and fresh taste you might expect from a stirfry that barely cooks the vegetables at all. Stovetop steaming to that color without going over into olivey, sulfurous territory would take longer and give you less tender broccoli as well, and boiling–don’t get me started. Moreover, you can keep the microwaved broccoli green and fresh-tasting longer if you microwave it just to the point you want or a little before and then pour off the drizzle of hot water and open the lid a bit. Even a head of broccoli that’s going bronzy-yellow after a week-plus in the fridge will generally perk up and be edible, not sulfurous-tasting, if you microwave-steam the florets instead of trying to deal with them some longer way.

Much the same can be said for corn on the cob. Microwave-steaming with only a little water and a lid cooks the cobs pretty fast, because the microwave energy heats the water inside the kernels as well as the water you added to the container, so it steams the corn from two directions at once.

Quantity and Layout

This method is pretty easy as long as you keep a couple of key factors in mind, namely how much food you’re trying to cook at once and how you lay it out in the container.

Raw corn cobs, shucked, rinsed and broken in half for microwaving

You wouldn’t want to try this for 20 ears of corn at a time, because the more food you microwave, the more energy and time it takes to get it all cooked, and it will cook less evenly and not be worth it. But for five or six people, you could probably do ok in one or two batches depending on what containers you have.

The other main thing about steaming ears of corn in the microwave is that you want them to cook as quickly and evenly as possible, just until they are cooked, which means you need to expose as much of the surface area of each cob as possible to the steam and, at the same time, to the microwave energy. So ideally you want them standing upright or at least diagonal, not lying flat on the bottom of the container or on each other if you can help it. You want the steam to circulate throughout the container, and you want the lid to keep it in and keep it focused on the corn.

A couple of ears left whole–lifting them up diagonally in the container helps them steam evenly.

For my containers, which tend to be 2.5 qt or liter snaplock boxes about 5 inches high, I break off the narrow “handle” and snap the ears in half after shucking them and rinsing off the last of the cornsilk threads. My hands are fairly strong so I just do it by hand, but you can also use a sharp knife to cut through the middle of each cob without too much sawing–the newer santoku-type knives or a microserrated paring knife would work pretty well. I can fit 3-4 ears’ worth of corn halves into one container, and I’ve done up to 8 ears of corn using two old-Pyrex mixing bowls, one over the other as a lid for a sort-of spherical container, so probably if I tried I could fit 6-7 whole ears into two large snaplocks, one used upside down as the lid. But I suppose your ability to try tall microwave containers and tall food in general depends on the size and height of your microwave.

The setup for 6 half-ears of corn

In any case, once you have the ears or half-ears arranged as best you can, you want to drizzle about 1/4 to 1/2 inch of water–no more–into the bottom of the container, and then put a lid on fairly well sealed so that when the microwave heats the water molecules, most of the steam stays in the container and doesn’t escape. If you’re resting one snaplock box on top of the other for a taller container, the seal won’t be tight but it should still keep most of the steam in where it can go to work on the corn.

For 3-4 ears’ worth of corn, I usually microwave on HIGH for 5-6 minutes and then let it sit a few more minutes to continue steaming inside the sealed container. Usually that’s enough to get it cooked all the way around the cob without starting to wilt or wrinkle the kernels. For more corn, you’ll need more time, maybe 8-9 minutes for 6-7 ears, whether broken into halves or kept whole. Obviously check progress after letting it steam on its own for a bit, and add a minute or two extra of microwave time if you need it. When the corn is just cooked, the cobs should be steaming hot (I hope this is obvious), the kernels should no longer be hard or opaque and chalky-looking, the way raw corn kernels are, but slightly translucent, and they should give a little when you press lightly against them with your finger.

If you have to lay the ears flat to fit a shallower container, the top part of each cob is going to cook more than the underside, and the underside will still be visibly raw after several minutes. Try to keep to one layer of corn so they don’t block each other from the microwave energy and make sure to stop the microwave in the middle of the cooking time and roll the ears over so the less-cooked bottom halves get some steam. Maybe also raise the container up off the turntable an inch or so by setting it on top of an overturned microwaveable saucer, bowl or shallow snaplock box to let more of the microwave radiation reach the bottom.

When the ears are done, carefully open a corner of the lid away from your face and drain the hot liquid out. Serve with whatever you like on corn–my current preference is a sprinkle of smoked paprika or chipotle salsa, ideally with a squeeze of fresh lime–all the best of barbecue without the grill, the grease, the heat, the wait, or the cleanup. You can reheat any leftover ears in the same microwave-steam setup but for just a minute or so, or cut the kernels off for a stir-fry with mushrooms and onions or as a stuffing for mild or slightly hot peppers–microwave all the way if it’s really hot out.

Mangia bene, b’te’avon, eat nice and keep as cool as you can.