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 the answers — and more.

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What to look for when buying cooking oils

Here are some common types of cooking oils:

• Canola oil: Developed in Canada, canola is a portmanteau of “Canada” and “ola,” which the Canola Council of Canada says means “oil” (in which language, we’re not sure). It is made from a certain type of rapeseed (bred from Brassica napus and Brassica rapa), a member of the mustard family. Most canola oil is refined, giving it a high smoke point and making it useful for frying, sauteing and stir-frying. It is also common in baked goods and salad dressing, being a light, neutral oil that doesn’t add additional flavor to dishes. Most margarine is made from canola oil.
• Coconut oil: Depending on who you ask, coconut oil is either the coolest and healthiest oil out there or really terrible for you — a furious nutrition and wellness tug-of-war. 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, 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.
• Olive oil: This oil is made from the flesh of ripe olives, which are crushed without breaking the hard stones (or pits) inside. The most highly prized olive oil is designated “extra virgin” and is extracted mechanically; extra virgin olive oil 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. Spain, Italy, Greece, Turkey and Morocco lead the way in global olive production. In the U.S., California produces the bulk of the olive crop.
• Margarine: A solid or semi-solid butter substitute, margarine is also sometimes known as oleomargarine or oleo. Invented in 19th-century France, it was initially seen as a threat to the dairy industry in the U.S. because it was significantly cheaper than butter; dairy farmers even lobbied to ensure that artificial colors, which would make the white mixture appear more butter-like, would not be allowed. By World War II, however, most states had repealed margarine restrictions, and it remains common in grocery stores. Margarine can be used as a substitute for butter in most dishes and in some baked goods.
• Shortening: This term is widely used for any oil or fat that makes a baked product “short,” or tender. Butter, lard, margarine and even some oils can be considered shortening. However, in the U.S., 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 oil: Palm fruit oil is extracted from the fruit of the African oil palm, 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 bleached, de-gummed and deodorized to make the flavor more neutral and ensure a higher smoke point.
• Peanut oil: More than half the world’s peanut crop is crushed for oil processing. Native to South America, peanuts have been introduced all over the world and flourish in the U.S. South, parts of Africa and all over Asia. Organic, unrefined peanut oil is available, but far more common is refined peanut oil, which is neutral-tasting and has a very high smoke point. Peanut oil is commonly used for deep-frying, stir-frying and salad dressings.
• Soybean oil: Many oils marketed as “vegetable oil” are, in fact, soybean oil. This neutral-tasting, highly refined oil has a high smoke point, making it useful for deep-frying, stir-frying and baking. It is also a common ingredient in commercial processed foods. According to the Soy Info Center, the majority of the world’s soybean oil is processed via chemical extraction using hexane (more on that below).

Most cooking oils are pressed or extracted from fruit, 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 few terms you might see on cooking oil labels.

• Chemically extracted: Most non-organic commercial oils (like canola and soybean) use chemical extraction. Generally, the seeds are washed, heated, pressed, flaked and then flooded with hexane, a petroleum product that is amazingly efficient at extracting oil. 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 organic products.
• Expeller-pressed: This kind of oil is extracted via pressure using a screw-like press. Expeller pressing is much less efficient than chemical extraction — a significant portion of the oil is not removed from the original product — and thus expeller-pressed oils tend to be more expensive than chemically extracted oils.
• Cold-pressed: Because pressure and friction can cause the oil to heat up during pressing, some oils are pressed in cold environments or with the aid of 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 fatty acids and other particles and substances considered “impurities.” (Color is often removed along with them.) By design, refined oils are extremely neutral in taste.
• Hydrogenation: Very simply explained, hydrogenation is a chemical process that adds hydrogen atoms to the oil. Fully hydrogenated oil (like shortening and margarine) is solid at room temperature. As this article explains, the more an oil is hydrogenated, the higher the saturated fat.
• Virgin, extra-virgin: These are terms used to describe the pressing and refining processes as well as the final oil’s chemical composition. Generally, “extra-virgin” oils are cold-pressed mechanically (i.e. without the use of chemical extraction). These terms, while sometimes used to describe other oils (notably coconut), are most frequently associated with olive oil; the International Olive Council has created more specific standards for their use.
• 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. Oils with a high smoke point are useful in frying and high-heat cooking.

Sustainability of cooking oils

Deforestation

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

No oil made from a commodity crop is immune from the pesticide concerns present in conventional agriculture. Peanuts, for example, are rarely grown organically and are frequently intercropped with cotton, 96 percent of which is genetically engineered to be herbicide tolerant — which means 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).

Labor issues

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.

Top photo by Deyan Georgiev/Adobe Stock.