How Long to Boil Corn on the Cob

Boil fresh, husked corn on the cob for 3 to 5 minutes once the water returns to a boil, until the kernels are bright, plump and tender. Frozen full-size ears need 5 to 8 minutes, and corn boiled in the husk needs about 10 minutes.

Corn on the Cob Boiling Time Chart

The short answer to how long to boil corn is that fresh sweet corn needs very little time. The goal is simply to heat the kernels through and soften their starch, not to cook them for long. Every time below starts when the water returns to a full boil after the corn goes in.

Type of corn	Boiling time	Notes
Fresh ears, husked	3–5 min	Use 3 min for very fresh, tender ears, 5 min for larger or older ears
Fresh ears, in the husk	About 10 min	Husk and silk peel away more easily after cooking
Fresh mini cobs or halved ears	2–4 min	Cut ears heat through faster than whole ones
Frozen full-size ears	5–8 min	Lower straight from the freezer into boiling water
Frozen mini cobs (cold-water start)	8–10 min	Typical package method: cover with cold water, bring to a boil, then boil
Off-heat soak (fresh, husked)	10 min, holds up to 30 min	Boil water, turn off the heat, add corn and cover

If you only remember one number, use 4 minutes for fresh, husked sweet corn in a large pot of boiling water. That falls in the middle of the 3 to 5 minute range most extension services and test kitchens recommend, and it suits the majority of supermarket and farm stand ears.

What Affects How Long to Boil Sweet Corn

Fresh sweet corn is a quick-cooking vegetable, so a minute or two is the main difference between crisp and soft. A few factors decide where in the range your ears land.

Freshness and Variety

Sweet corn starts converting its sugar to starch as soon as it is picked. Corn eaten the day it is harvested is at its sweetest and most tender, and it needs only 2 to 3 minutes. Ears that have sat for several days taste starchier and benefit from the full 5 minutes. Modern supersweet and sugar-enhanced varieties hold their sweetness longer than older types, so supermarket corn of these varieties still cooks quickly.

Size of the Ears

Large, thick ears take a little longer than small ones because there is more cob to heat. Mini cobs and ears broken in half cook in 2 to 4 minutes. A crowded pot also matters: adding many cold ears drops the water temperature, so the clock should start only when the water returns to a boil.

Husked vs in the Husk

Leaving the husk on insulates the kernels, which is why corn boiled in the husk needs roughly double the time, about 10 minutes. The upside is that the silk slips off with the husk once the corn is cooked. Husking first remains the most common method and gives the most predictable timing.

Fresh vs Frozen

Frozen corn on the cob has already been blanched before freezing, so it is partly cooked. It still needs 5 to 8 minutes in boiling water to heat the dense, frozen cob all the way to the center. Some package directions start frozen mini cobs in cold water and then boil them for 8 to 10 minutes; follow the package when one is provided.

How to Pick and Prep Corn for Boiling

Good corn makes the timing easy. Choose ears with bright green, snug husks that feel slightly damp, and silk tassels that are brown and a little sticky rather than black or dry. Feel through the husk for full, plump kernels along the whole ear. If you can peek at the kernels, they should be glossy and release a milky liquid when pressed with a fingernail. Dented or doughy kernels are a sign the corn is past its best.

Cook corn as soon as you can after buying it. If you have to wait, refrigerate the ears unhusked and plan to use them within 1 to 2 days for the best flavor. To prep, pull the husks down and snap them off at the base, then rub away the silk with your hands or a dry vegetable brush. Trim off any damaged tips and the stalk end if the ears are too long for your pot. Large ears can be snapped or cut in half for easier serving.

How to Boil Corn on the Cob Step by Step

This method works for 4 to 8 ears of fresh, husked corn. Use a pot large enough that the ears are fully submerged, roughly 4 to 6 quarts of water for 4 ears.

1. Bring a large pot of water to a full boil. Fill it about two-thirds full so the water covers the ears once they go in.
2. Husk and clean the corn. Remove the husks and silk, and cut the ears in half if they do not fit.
3. Add the corn to the boiling water. Lower the ears in with tongs. The boil will slow down briefly.
4. Start timing when the water returns to a boil. Cook fresh ears for 3 to 5 minutes, frozen ears for 5 to 8 minutes, or ears in the husk for about 10 minutes.
5. Check one ear. Lift it out and test a kernel as described below.
6. Drain and serve. Remove the ears with tongs, shake off excess water and serve with butter, salt and pepper.

The Off-Heat Method

For a more forgiving approach, bring the water to a boil, turn off the heat, add the husked ears and cover the pot. Let them sit for about 10 minutes. America’s Test Kitchen notes that this method brings the kernels into the 150°F to 170°F (66°C to 77°C) range where the starch softens but the kernels stay snappy, and the corn can stay in the water for up to 30 minutes without overcooking. It works well when you are not sure exactly when everyone will sit down.

How to Tell When Boiled Corn Is Done

Boiled corn is done when the kernels turn a deeper, brighter yellow, look plump and glossy, and pierce easily with the tip of a knife or a fork. Bite or press a kernel: it should pop with sweet juice and feel tender with a slight crunch. If the kernels are still pale and taste chalky or starchy, give the ears another minute.

Overcooked corn is easy to spot. The kernels look wrinkled or deflated, the skins turn tough and chewy, and the flavor goes flat. Once you see that, the corn cannot be reversed, which is why it pays to check early. With fresh sweet corn, erring on the shorter side of the range is usually the better choice.

How to Keep Boiled Corn Warm

The easiest way to keep corn warm is to leave it in the pot. Turn off the heat as soon as the corn is done, cover the pot and let the ears sit in the hot water for up to 30 minutes; because the water is no longer boiling, the corn stays warm without turning mushy. For a crowd, you can also wrap drained ears in foil or a clean kitchen towel and hold them in a covered dish in an oven set to about 200°F (93°C).

For buffets and parties, USDA advises holding hot foods at 140°F (60°C) or above. A slow cooker on the warm setting with a little hot water in the bottom works well for this. Plan to serve within a couple of hours, and refrigerate leftovers promptly.

How Long Cooked Corn on the Cob Lasts

Cooked corn on the cob keeps for 3 to 4 days in the refrigerator, in line with USDA guidance for cooked leftovers. Let the ears cool briefly, then wrap them individually in plastic wrap or foil, or place them in a sealed container, and refrigerate within 2 hours of cooking. For longer storage, freeze cooked ears or cut-off kernels in freezer bags; they keep their best quality for about 3 to 4 months.

To reheat, drop refrigerated ears into boiling water for 1 to 2 minutes, or microwave them wrapped in a damp paper towel for about 1 minute per ear. Leftover kernels cut from the cob are also good stirred cold into salads and salsas, or warmed through in soups, chowders and fritters.

Frequently Asked Questions

These are quick answers to the questions people ask most often about boiling corn on the cob.

How long do you boil corn on the cob?

Boil fresh, husked corn on the cob for 3 to 5 minutes after the water returns to a boil. Frozen ears take 5 to 8 minutes, and corn boiled in the husk takes about 10 minutes.

Should you put corn in cold or boiling water?

Fresh corn goes into water that is already boiling, which gives the most predictable timing. Some frozen mini cob packages call for a cold-water start followed by 8 to 10 minutes of boiling, so check the bag for frozen products.

Can you overcook corn on the cob?

Yes. After about 10 minutes of hard boiling, fresh sweet corn usually turns soft and chewy and loses sweetness. If you need to hold it, take the pot off the heat and keep the corn in the hot water rather than letting it keep boiling.

Do you need to thaw frozen corn on the cob before boiling?

No. Frozen ears can go straight into boiling water; just add a few minutes and boil them for 5 to 8 minutes total.

Should you add salt to the water for corn?

It is not necessary. Many extension services suggest unsalted water and seasoning the corn at the table, where salt and butter flavor the kernels more directly.

Sources: USDA Food Safety and Inspection Service; FoodSafety.gov; Purdue Extension; Ohio State University Extension; Clemson Cooperative Extension Home & Garden Information Center; Penn State Extension; America’s Test Kitchen.