Real Food Encyclopedia | Cooking Oils

Like salt and black pepper, you probably reach for cooking oil for just about every meal you make. But have you ever wondered about the history of your canola oil, or what makes fancy extra virgin olive oil so expensive? Or what the heck margarine really is? Read on for all of this and more.

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What to Look for When Buying Cooking Oils

Here are some commond types of cooking oils:

  • Canola: a Canadian-developed-and-marketed oil pressed from a type of rape seed (Brassica napus or Brassica rapa), a member of the mustard family. The word “canola” is a portmanteau of “Canada” and “ola,” which the Canola Council of Canada says means “oil” (in which language, we’re not sure). Most canola oil is refined, meaning that it has a high smoke point, and is useful for frying, sautéing and stir-frying. It is also widely used in baking, as a component of salad dressings and to make margarine. It is a light, neutral-tasting oil, meaning that it doesn’t add additional flavor to your dish or baked good.
  • Coconut Oil: unsurprisingly, comes from fruit of the coconut palm, and is in the middle of a furious nutrition and wellness tug-of-war as either the coolest/healthiest oil out there, or a fat that’s really terrible for you. Most commercial coconut oil, which is frequently referred to as RBD (refined, bleached, deodorized) coconut oil, is made from copra, the dried meat of the coconut. Virgin coconut oil is 92 percent saturated fat and is solid at room temperature, and white in color. Depending on how it is processed, it can have a mild to strong coconut flavor. Refined coconut oil is odorless and has a much higher smoke point than virgin oil. Here is a nice guide to selecting a good coconut oil.
  • Olive Oil: comes from olives that must be harvested ripe and undamaged, and crushed without breaking the hard stones inside the fruit. As you might guess, Spain, Italy, Greece, Turkey and Morocco lead the way in global olive production. In the US, California produces the bulk of the olive crop. The most highly prized olive oil is designated “extra virgin,” and is extracted mechanically. It is fruity and peppery, with a low smoke point, and can range in color from yellow to green. Oils marked simply “olive oil” are a blend of extra virgin and refined olive oils.
  • Margarine: (aka, oleomargarine or oleo), a solid or semi-solid substitute for butter, was invented in 1869 in France. In the US and elsewhere, margarine was seen as a threat to the dairy industry because it was significantly cheaper than butter. Dairy farmers even lobbied to ensure that artificial colors, which would make the white mixture more butter-like, were not allowed. Most states had repealed margarine restrictions by World War II. Margarine can be used as a substitute for butter in most dishes and in some baked goods.
  • “Shortening”: is a term used for any oil or fat that makes a baked product “short,” or tender. Butter, lard, margarine and even oils can be considered shortening. However, in the US, vegetable shortening usually refers to a product like Crisco, a solid mass of hydrogenated vegetable oil, white in color and used in baking and frying.
  • Palm Fruit Oil: extracted from the pulp of the fruit of the African oil palm trees, while palm kernel oil is made from the inner, harder kernel. Indonesia, Malaysia, Nigeria, Thailand and Cambodia account for most of the world’s production of palm oil. Unfortunately, oil palm plantations are wreaking serious environmental havoc in these places. Organic, sustainably grown red palm oil is available. More common is refined palm oil, which is much more neutral-tasting after refinement (which includes bleaching, degumming and deodorizing) and has a higher smoke point.
  • Peanut Oil: comes from peanuts, which hail from South America, where they were “discovered” by the Spanish and the Portuguese, and subsequently introduced all over the world. They flourished (and still do) in the US South, parts of Africa and all over Asia. According to the weirdly fascinating book “Vegetable Oils in Food Technology,” the French and the British began importing peanuts for oil pressing in the middle of the 19th century. Globally, over 50 percent of the world’s peanuts are crushed for oil processing. Organic unrefined peanut oil is available and is quite delightful. Far more common is refined peanut oil, which is a neutral-tasting oil and has a very high smoke point. It is commonly used for deep and stir-frying and in salad dressings.
  • Soybean Oil: for production, the soybean is allowed to mature on the plant, after which it is harvested and prepared for processing into oil. The Soy Info Center says that over 90 percent of the world’s soybean oil is processed via chemical extraction, using hexane (more on hexane below). Soybean oil is neutral tasting, highly refined and has a high smoke point, making it useful for deep and stir-frying and for baking. It is also used in commercial, processed food. Many oils marketed as “vegetable oil” are, in fact, soybean oil (but sometimes also safflower oil).

Most cooking oils are pressed or extracted from fruit, vegetable seeds or nuts. The ways in which various oils taste and perform in the kitchen have a great deal to do with the way they have been produced and refined (or not refined, as the case may be). Below are a couple of buzzwords you might notice on cooking oil labels that are helpful to know.

  • Chemically Extracted: Most non-organic, commercial oils (like soybean, corn, canola oils) use chemical extraction to remove the oil from the seeds. Generally, the seeds are washed, heated, pressed, flaked and then flooded with hexane, a petroleum product that is frightfully efficient at extracting oil from seeds. Unfortunately, hexane is dangerous to those who work with it and is difficult to dispose of safely. (The jury is still out as to whether consuming hexane-extracted oils is safe.) It should be noted that the FDA does not require that hexane extraction be listed on food labels, but it is not allowed in certified organic products.
  • Expeller-Pressed: The oil is extracted via pressure by using a screw-like press. Expeller pressing is much less efficient than chemical extraction — a significant portion of the oil is not removed — and thus expeller-pressed oils tend to be more expensive than chemically extracted oils.
  • Cold-Pressed: Because pressing oil can cause the oil to heat up (due to pressure and friction), some oils are pressed in cold environments or by using a cooling apparatus. Cold pressing is supposed to preserve flavor and nutrients.
  • Refined: Some oils are further refined after the chemical extraction or pressing process. Refinement removes various compounds in the oil, including color and other particles, fatty acids and other substances considered “impurities.” Refined oils are extremely neutral in taste, by design.
  • Hydrogenation: Very simply explained, oils are hydrogenated via a chemical process that adds hydrogen atoms to the oil. As this article explains, the more an oil is hydrogenated, the higher the saturated fat. Fully hydrogenated oil (like shortening and margarine) is solid at room temperature. Chemistry is magic!
  • Virgin/Extra-Virgin: These are terms used to describe the pressing and refining processes of the oil, as well as the chemical composition. Generally, “extra-virgin” oils are cold pressed mechanically (i.e., without the use of chemical extraction). These terms are most frequently associated with olive oils, which are defined by the International Olive Council. They are also more recently being used to describe coconut oil.
  • Smoke Point: The temperature at which smoke appears when the oil is heated. In general, the more refined the oil, the higher the smoke point. High smoke point oils are useful in high-heat cooking.

Sustainability of Cooking Oils

Palm Oil, Soybean Oil and Rainforest Destruction

Oil palm plantations are wreaking serious environmental havoc in Indonesia, Malaysia, Nigeria, Thailand and Cambodia. The situation is quite dire in Indonesia and Malaysia, where tropical forests, home to orangutans and Sumatran tigers (along with many other important species), are being destroyed and degraded at a truly heartbreaking rate, even outstripping deforestation rates in the Brazilian rainforest. (And two species of orangutans in Borneo are listed as endangered or critically endangered.) Not only does rainforest destruction cause habitat loss, but slash-and-burn clearing also releases greenhouse gasses, which contributes to climate change. Check out this interactive guide to the issues with palm oil from The Guardian. 

In addition, the demand for soybean oil and other soy products is affecting the rainforest in South America, as large tracts of land are clear-cut to make way for soy plantations.

Pesticides and Cooking Oils

Peanuts (mostly used for peanut oil) are infrequently grown organically and are frequently intercropped with cotton, 96 percent of which is genetically engineered to be herbicide tolerant (which means lots and lots of herbicides on the crop).

According to the Canola Oil Council of Canada, 99 percent of canola planting in Canada is Monsanto-created seed, genetically engineered to be resistant to Roundup (aka, glyphosate), leading to copious amounts of glyphosate being used on canola crops.

Labor Issues with Coconut Oil

Coconuts are grown on plantations across the tropics, but Indonesia, the Philippines, India, Brazil and Sri Lanka are the top global producers. As Maddie Oatman in Mother Jones pointed out a few years ago, coconut farmers are frequently paid very little and exposed to dangerous pesticides. Coconuts can also be dangerous to harvest.

Using Cooking Oils

Storing Cooking Oils

High-quality cooking oils should come in a dark glass bottle, as light increases the possibility of rancidity. However, the more refined the oil, the less likely it is to go rancid. Keep cooking oils in a dark, cool place to prolong their life.

Other Types of Cooking Oils

Cooking oil can be made from many different nuts and seeds. Some other oils of importance (in addition to those discussed above) in the US and globally include:

  • Corn Oil: is extracted from the germ of field corn kernels. It was first produced in 1889. Most corn oil is chemically extracted and highly refined. Refined corn oil has a high smoke point.
  • Cottonseed Oil: pressed from the seeds of the cotton plant, and usually highly refined. It is frequently turned into margarine and shortening, and used in processed foods and for frying. China, India and the US are the top producers of the oil.
  • Grapeseed Oil: a byproduct of the wine industry, has a neutral taste and high smoke point, and is useful as an alternative to canola for frying and baking and in salad dressings.
  • Safflower Seed Oil: which is made from the seeds of a lovely yellow flower related to the sunflower (and used since antiquity for a natural yellow dye). Safflower seed oil is neutral tasting, usually highly refined, and can be used for deep-frying and in baking. Mexico, Kazakhstan and India are the top global producers of safflower seeds.
  • Sunflower Seed Oil: pressed from the seeds of a type of sunflower, is also usually highly refined and used in processed foods and baked goods. Like safflower seed oil, refined sunflower seed oil has a high smoke point, is neutral tasting and can be used for deep-frying and for baking.
  • Sesame Oilis an important cooking oil in Chinese, Japanese, Korean and Indian cuisines. It is less commonly refined than the other cooking oils on this list, and has a nice nutty flavor. Toasted sesame oil, made from the toasted seeds, has a very strong sesame flavor and is most commonly used as an oil for drizzling and in sauces.
  • Others: Other nut and seed oils include argan, walnut, almond, pistachio, pumpkin and avocado oils. These are usually unrefined, quite pricey and used for drizzling and dipping.

Cooking Oil Nutrition

  • Canola oil is low in saturated fat — the least saturated of all cooking oils, according to the US Canola Association — and high in omega-3 fatty acids and monounsaturated fat which is the good kind of fat. It’s also a good source of Vitamins E and K.
  • Virgin coconut oil is 92 percent saturated fat and is solid at room temperature, and white in color. Virgin coconut oil has, of late, become the darling of the natural food world, purported to help with weight lossoral health and even Alzheimer’s disease.
  • After a byproduct of hydrogenation, trans fats, were shown to increase “bad” cholesterol, many margarine and shortening manufacturers devised ways to advertise their products as “trans fat free” by switching oil types used in the manufacturing process.
  • Olive oil is low in saturated fat, and high in Vitamins E and K. The oil is high in monounsaturated fatty acids, which have been linked to heart health and lowered cholesterol levels.
  • Peanut oil is high in Vitamin E and omega-6 fatty acids.
  • Soybean oil is very high in Vitamin K, has some Vitamin E and is rich in omega-6 fatty acids, and to a lesser extent, omega-3 fatty acids.