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Ingredient Guides: Corn Oil

Corn oil is one of the more common oils on supermarket shelves and in pantries. Here’s what you need to know about it.

Liudmyla Chernetska / Depositphotos
By Dim Nikov,
editor-in-chief of Tastyble, formally trained chef, and author of Cooking Methods & Techniques: A Crash Course on How to Cook Delicious Food at Home for Beginners.

Walking through the supermarket’s oil aisle, you might find your gaze landing on a familiar yet often overlooked contender: corn oil.

Think about it — corn has been with us for ages. Ancient civilizations in the Americas didn’t just munch on maize; they celebrated it, seeing it as a symbol of life and abundance.

Fast-forward to today, and while corn has found its way into countless dishes worldwide, its oil often takes a back seat. But here’s the thing: corn oil, with its gentle flavor and adaptability, deserves a spot in our kitchens.

A word to the wise: not all corn oils are born equal. Some shine brighter than others, both in taste and quality. And since we all want the best bang for our buck, we’ve pieced together this guide to help you pick out the best.

What Is Corn Oil?

Corn oil, also known as maize oil in British English, is a cooking oil made from the germ of the corn. It has a light color, a neutral flavor, and a high smoke point, making it suitable for high-heat cooking methods like searing, sautéing, grilling, and broiling.

It’s also affordable and can be found at most grocery stores, making it an appealing choice for home cooks on a budget and those who live in rural areas.

Is Corn Oil Good For You?

Corn oil contains mostly unsaturated fat — the good, heart-healthy kind known to improve your blood cholesterol.

It’s also a rich source of vitamin E. According to the USDA’s FoodData Central, 1 tablespoon (14.78 ml) of corn oil has 3 mg of vitamin E. That’s 20% of the antioxidant’s recommended dietary allowance. Regardless, corn oil isn’t as nutrient-rich as certain other oils, be it cold-pressed avocado oil or extra virgin olive oil.

Whether corn oil can be considered a “healthy” oil or not is disputed. Like other seed and vegetable oils, corn oil contains omega-6 fatty acids. In small amounts, this family of fatty acids can be good for the heart. However, ingesting too much of them can cause inflammation. As a result, some experts characterize corn oil as not the healthiest choice, while others suggest that the solution is eating more omega-3s, not fewer omega-6s.

In the end, you’ll have to make the call based on the information and beliefs you have about the oils you use for cooking. The only thing everyone can agree on is that using too much oil, regardless of the type, is never a good thing.

How Corn Oil Is Made

To make corn oil, the first step is to soak the corn, which softens the kernels. The wet corn kernels are then fed through a series of mills and centrifuges, which separate them into their constituents.

The fiber is used for feeding animals. The starch is sold as cornstarch or turned to sugar. The yeast, for the fermentation of ethanol. The edible oil is extracted from the germ, which constitutes just 6-8% of the corn grain’s weight.

The corn oil is extracted from the kernels first by mechanical pressing, and then using chemical solvents like hexane. The oil from the first pressing is the purest and richest in nutrients; that from the chemical pressing is refined, which gives it a higher smoke point and longer shelf life.

Once extracted, the corn oil is bottled, labeled, and sent to wholesalers and supermarkets for distribution and retailing.

Types of Corn Oil

Corn oil can be either unrefined or refined, depending on the extraction method.

Unrefined corn oil, also known as “first cold pressed,” “cold pressed,” or “virgin” corn oil, is extracted with mechanical means, without the use of elevated temperatures or chemical solvents. It has a golden yellow color and a potent aroma reminiscent of corn. However, it burns more readily at high heat and has a generally shorter shelf life.

Refined corn oil is odorless and neutral-flavored because it has been bleached and lightened. It’s suitable for reuse and high-heat cooking as it can withstand high heat without breaking down, smoking, and becoming bitter.

It’s important to note that the term “bleaching,” despite its name, does not mean that the oil was processed with bleach. Rather, the oil is passed through a clay filter that removes the natural pigments that give it color, aroma, and flavor. Those pigments also lower the oil’s smoke point and shorten its shelf life.

Choosing the Best Corn Oil

If you can come across it and are willing to pay up for it, opt for 100% unrefined corn oil (usually marketed as first cold pressed, cold pressed, or virgin corn oil). It’s the purest oil with the most natural taste that has undergone the least processing.

If you’re looking to save money, refined corn oil is about the same as other vegetable and seed oils in both price and quality. (Though not the best for high-heat cooking, extra virgin olive oil can be a more healthful alternative and is often sold discounted.)

You can get more for your money if you buy corn oil in larger quantities, as bigger containers cost less per liquid ounce to buy. Still, only buy as much as you can use up within 6 months after opening, or the oil can go rancid.

Corn oil kept in dark-glass containers, tin cans, and opaque plastic bottles should be preferred over that stored in clear plastic bottles, which offer minimal protection from the sun.

Look for a harvest date or best-by date. The harvest date indicates when the oil was produced — the more recent it is, the better. The “best-by” date is the estimated time by which the corn oil will maintain its best quality, with a farther-out date indicating a more recently produced oil.

The terms “natural” and “all natural” have little meaning, if any at all. “Non-GMO” means that the oil does not come from genetically engineered corn crops (these days, most corn is GMO). And if the oil is labeled “organic,” this tells you that the corn was not treated with pesticides during growing.

Take a look at the storage conditions for the corn oil in the supermarket. Is it put close to a window or entrance, which can let in heat? If it is, consider getting it from somewhere else — heat can cause oil to turn rancid more quickly.

Storing Corn Oil

Put your corn oil in a cool space shaded from sunlight, like the pantry, kitchen cupboard, or a spacious closet. Avoid storage spots such as atop the fridge or dishwasher, near the stove or oven, or close to an A/C vent or hot water pipe.

If you buy your oil in bulk, pour it out into a stainless-steel oil dispenser with a sealable spout or a dark-green glass bottle with a tight-fitting lid. Keep the containers airtight at all times; oxygen exposure leads to oxidation, which in turn causes rancidity.

Corn Oil’s Shelf Life

If stored in a cool and dark place, unopened corn oil will last up to 2 years. Don’t forget the importance of selection at the grocery store — the newer the oil was when you bought it, the longer it will keep.

After opening, corn oil steadily deteriorates until it eventually becomes rancid. As a general rule, opened corn oil should be kept airtight and used up within 3 to 6 months for best quality.

Frequently Asked Questions

Where to buy corn oil?

Corn oil is carried by most grocery stores. Look for it in the cooking oils section. If you prefer to shop online, you can find corn oil at Amazon, Kroger’s, and Walmart, among others.

Why is corn oil cheaper than other oils?

Corn is a staple crop on a global level, with the United States as the largest producer, consumer, and exporter. With abundant production and an efficient extraction process, corn oil is generally cheaper than most other vegetable and seed oils in the supermarket.

What’s the smoke point of corn oil?

The smoke point of corn oil is 450 °F (232 °C). If you’re planning to use the oil more than once, bear in mind that the smoke point will become lower with every reuse.

Are corn oil and sunflower oil?

Corn oil and sunflower oil are both used for cooking, and they have a neutral taste and a high smoke point. Nonetheless, these two oils are not the same; corn oil comes from the germ of the corn and sunflower oil is obtained from sunflower seeds.

Can you mix corn oil with other oils?

The short answer is yes. If you’re looking to reduce the cost of cooking or raise the smoke point of another oil, you can blend corn oil with it. Any ratio will work.

Can you cook with corn oil?

Yes, corn oil is one of the most affordable and versatile cooking oils in the supermarket. It’s economical, capable of withstanding high heat, and doesn’t impart a strong flavor onto your dishes.

Can you deep-fry with corn oil?

Definitely, you can deep-fry with corn oil. If you filter it from food particles and store it in an airtight container, you can also reuse it. Just don’t overdo it — the oil can weaken and become hazardous at high temperature if reused too many times.

Can you sear a steak with corn oil?

So, you’re about to sear a steak? Corn oil is a great option. It doesn’t have a strong flavor and it can stand up to the high heat. Simply start by greasing the pan with it, heat it until it’s ready to sear, and then add the steak.

Is it okay to put corn oil on burgers?

Yes, corn oil can be used to grease burgers so they don’t stick to the grill or pan when they’re being cooked.

Does corn oil lose calories when heated?

No, corn oil doesn’t lose calories when heated. Heat doesn’t alter the caloric content of oil in any way, and corn oil is no different.

My corn oil smells weird when heated. What does this mean?

If your corn oil has a bad odor or flavor when heated, it is likely rancid. Throw it away and don’t eat it; rancid oil won’t necessarily make you sick, but it can irritate your gut.