The Complete Guide To Cooking Oils: 8 Commonly-Used Culinary Oils

The Complete Guide To Cooking Oils: 8 Commonly-Used Culinary Oils


17 minute read

You love to cook great tasting food. You love to experiment with new recipes. You especially love all there is to learn about food––and nutrition research is continually updating with surprising and sometimes unsettling information, so there’s always a lot to learn.

One of the most common issues many cooks make is actually quite basic––what type of cooking oil to use. It's a common issue because oil is present in so much of our food, whether it's homemade, from a restaurant, or commercially-produced. It's an issue because there are so many varieties to choose from, and there's a lot of conflicting information.

There are as many different types of cooking oils as toothpastes, and choosing one isn't easy. Like many people, you might be influenced by attractive packaging, an authentic-sounding brand name, or descriptors that sound legit. Perhaps a recipe you want to try calls for a particular type of oil, but you're not sure it's a healthy choice, though it may enhance the taste.

Vegetable oils, seed oils, nut oils––how do you know which ones are nutritious and which ones aren't and why? What is wrong with refined oils, and what types of oils are highly refined? Is fat type an indication of the nutrition index of an oil? Which oils are suitable for cooking with, and which ones are best consumed raw? What does an oil’s smoke point tell us about it?

We're going to answer all these questions and more in Priority Chef';s Complete Guide To Cooking Oils. Here you’ll discover which oils are better for you than others, which ones are best for drizzling over salad, sauteeing at low temperatures, and stir-frying at high heat.

How To Use This Guide

We concentrated this guide on eight commonly-used culinary oils. But first, we provide essential information about different oil types, extraction processes, refined versus unrefined oils, heating and oil stability, and storage. We recommend consuming all the information provided here to gain a comprehensive understanding of cooking oils. However, if you’re short on time and want to jump ahead to read a specific section or learn about a particular oil, use the menu below:

Vegetable Oils

Nut Oils

Industrial Seed Oils

Animal Oils

Virgin, Cold-Pressed & Expeller-Pressed

What Head Does To An Oil’s Stability

How To Store Cooking Oils

Coconut Oil

Olive Oil

Rice Bran Oil

Palm Oil

Avocado Oil

Flaxseed Oil

Sesame Oil

Walnut Oil

oils

Vegetable Oils

These are oils extracted from plants and bottled for cooking and baking. They’re also found in many commercially processed foods, such as potato chips, salad dressings, and packaged cookies. Vegetable oils are often extracted using heat and chemicals, a refining process that alters an oil’s chemical structure, rendering it much less nutritious than unrefined oils.

Not all vegetable oils are bad for you, though. It depends on the plant they’re extracted from, the fatty acids they contain, and how they’re processed. For example, plant oils like coconut and olive oil are incredibly nutritious. Many vegetable oils have a high level of omega-6 fats, which health experts recommend only in moderation because they may promote inflammation (1). Examples of these types of oils are sunflower, rice bran, and sesame oils.

Nut Oils

Botanically speaking, a nut is actually a fruit with an edible seed. When it comes to nut oils, it depends on the type of fat and how the oil is expelled.

Peanut oil, for example, is higher in monounsaturated fat than polyunsaturated or saturated, but also contains high levels of omega-6 fatty acids. It has a high smoke point, however, which makes it one of the better oils with which to cook.

Almond oil has less polyunsaturated fat than peanut oil, making it a healthier option, but it has a lower smoke point, so it’s better consumed raw. Its mild, nutty flavor makes it an excellent drizzled topping for fresh salads.

Just one tablespoon of walnut oil contains five times the recommended daily intake of omega-3 fatty acids, which have several health benefits. It’s also higher in monounsaturated fats, but it has a low smoke point, so it is more nutritious when consumed raw.


QUICK FACT: Walnuts are the only nut that contains omega-3 fatty acids, rendering them the healthiest nut. According to the Doctrine of Signatures in Traditional Chinese Medicine, a walnut's appearance resembles the brain, making it beneficial to brain functioning.


Industrial Seed Oils

These are some of the worst oils you can consume. They are highly-processed vegetable oils from plants such as corn, grapeseed, and soybeans, containing chemical byproducts as a result of high-heat processing and chemical additives that cause oxidation of fatty acids. Industrial seed oils are known contributors to chronic inflammation, and they’re high in omega-6 fatty acids. Examples are safflower, rice bran, and canola oils. See the resources section to learn more about the history of industrial seed oils and why they’re harmful to your health.

Animal Oils

Many natural animal fats used as oils contain healthy amounts of saturated fat. Examples are butter and ghee from pasture-raised cows. Ghee is one of the best sources of animal fats available, and it’s easy to make at home. Use ghee liberally in your cooking, and butter in moderation.

Virgin, Cold-Pressed, Expeller-Pressed––What Do These Mean?

Cold-pressing involves crushing seeds, without heat or chemicals, to extract the oil. Because it uses very low-temperatures, cold-pressing retains the antioxidants and nutrients that heat destroys.

Similar to cold-pressing, expeller-pressed means oil is produced using pressure and friction. Seeds are squeezed through a barrel-like cavity to extract oils. This process involves higher temperatures than cold-pressing, but it's void of the chemicals used to refine oils.

What about virgin, extra-virgin, or no indication of either? If you've ever spent 10 minutes standing in front of a dozen different olive oils in your local supermarket, wondering which one to buy, you're facing a pretty common problem. You've probably heard that some manufacturer's mix olive oil with lower quality oils and slap an "extra-virgin" label on it. If you haven't, then it’s an issue of which you should be aware.

Basic olive oil, without the virgin or extra-virgin stamp, is simply oil extracted from olives. However, the extraction process may use high heat or chemicals, which may strip its nutritional components and increase its acidity.

Virgin olive oil is better because it's less acidic than ordinary olive oil. Although chemicals may be used in the extraction process, they're less concentrated, so the oil retains most of its nutritional components.

Extra virgin olive oil is the highest standard. It contains less than 1% acidity because no chemicals are used in the extraction process, only low-temperature pressure. This allows the oil to retain most or all of its nutrients.

So, how do you know what the label reads is accurate and honest? There are a few ways to spot a fake oil:

  • Look for international certification. This indicates that an oil has met industry standards.

  • Price is usually a good indication because a higher-quality oil involves more effort and cost to produce, which price reflects. Paying a little more almost certainly guarantees a safer, better oil.

  • Extra-virgin olive oils are stored in glass bottles, not plastic ones. Clear plastic allows in light, which can break down an oil’s chemical composition. Good quality olive oils are usually housed in dark green glass bottles.  

What Heat Does To An Oil's Stability

Its resistance to heat determines an oil's stability. Each oil has a smoke point, which is the primary feature to pay attention to when choosing a cooking oil. The smoke point is when the flavor and nutritional integrity of an oil begins to break down, indicated by when it begins to burn and smoke. Once this occurs, it becomes high in oxidized fat, making it unstable, and studies suggest such oils contribute to cell damage and inflammatory diseases (2).

There is a significant variation in smoke point across cooking oils. Still, generally, refined oils have a higher smoke point because they contain less fatty acids and impurities that cause the oil to smoke. Oils high in polyunsaturated fats have a lower smoke point. For example, coconut oil's smoke point is very high 450°F, owing to its high saturated fat content.

Oxidation and hydrolysis also cause oils to become rancid (3). But some oils are more resistant to oxidation than others, depending on how saturated they are. Saturated fat contains hydrogen molecules that have a single bond between carbon molecules. Monounsaturated fats have one double bond, while polyunsaturated fats have two or more. Double bonds, such as those found in polyunsaturated fat-based oils, are more reactive and sensitive to heat than single bonds, and cooking with them should be avoided. Oils high in saturated fats and monounsaturated fats are fairly resistant to heat (3).

What actually happens when an oil is exposed to heat? The high temperatures break down the polyunsaturated fatty acids, and they become toxic compounds. Exposing our bodies to these harmful compounds may promote inflammatory diseases, digestive illnesses, cancer, and birth defects (4). As often as you can, choose saturated or monounsaturated oils for cooking, and consume polyunsaturated fats raw and in moderation.


QUICK FACT: Monounsaturated fats, such as those contained in avocado and olive oil may increase nutrient absorption.


How To Store Cooking Oils

There are three basic things to remember when it comes to storing cooking oils: light, heat, and air are not your friends. Light quickly degrades cooking oils, which is why you find higher-quality oils like extra-virgin olive oil in dark glass bottles. Cold preserves cooking oils longer, but they don’t require refrigeration unless your kitchen temperature is above 64°F. That said, keep your cooking oils as close to refrigerator temperature as possible. Air also degrades the quality of your cooking oil and will render it tasteless. Ensure you choose a variety that is stored and secured with an airtight lid.

8 Common Culinary Oils

Coconut Oil

Fatty Acid Content: 90% saturated fat

Smoke Point: 450°F

Shelf Life: 2 years

Coconut oil is one of those blessings of nature. It is very high in healthy saturated fat, and because of that, it has a high smoke point, making it one of the best oils to cook with. It contains naturally-occurring medium-chain triglycerides, which have proven microbial properties and potential weight loss benefits. Coconut oil has a distinct flavor and aroma, which is exceptionally pleasant in curries, stir fries, smoothies, and buttered coffee.

Perhaps in competition with extra virgin olive oil, unrefined, cold-pressed coconut oil is arguably the best culinary oil for its incredible health benefits. And it’s not just for cooking. Coconut oil is an excellent skin moisturizer with a low, but naturally-occurring SPF. It also whitens teeth and prevents plaque build-up when used as a mouthwash––an Ayurvedic technique known as "pulling."

Olive Oil

Fatty Acid Content: 75% monounsaturated fat (oleic acid)

Smoke Point: 410°F

Shelf Life: A few months after opening

There's a reason why the Mediterranean diet is recognized as one of the healthiest diets in the world––it uses a lot of olive oil! Olive oil is high in antioxidants and may help increase good cholesterol and lower bad cholesterol. As we described, extra virgin olive oil is the most nutritious type of olive oil because it is most pure, less acidic, and isn';t exposed to high heat. Although olive oil does contain some polyunsaturated fatty acids, it is still fairly resistant to heat. However, low-temperature cooking like sauteing or raw consumption is best.

While olive oil is the proclaimed best oil to cook with in 2020, based on current nutritional research, production in the olive oil industry is dubious, so ensure you’re always choosing a reputable brand and look for those signs of authenticity.

Rice Bran Oil

Fatty Acid Content: 20% saturated fat, 35% polyunsaturated fat, 39% monounsaturated fat

Smoke Point: 450°F

Shelf Life: 1–2 years

Rice bran oil is one of those oils that experts can't agree on. Is it healthy because it lowers cholesterol and has loads of vitamin E? Or is it unhealthy because it's refined, may contain high levels of arsenic, and can cause stomach discomfort (5)? We’ll let you weigh those contrasting features and be the judge.

Rice bran oil is an industrial seed oil that is produced by extracting the oil from the grain’s outer husk. Then it’s refined, separated, and filtered for maximum purity. It has a high smoke point, which makes it great to cook with, especially for its reputation as the best oil for tempura––yum! But use this one in moderation, and limit high-heat cooking with this oil to a minimum.

Palm Oil

Fatty Acid Content: 49% saturated fat, 9% polyunsaturated fat, 37% monounsaturated fat

Smoke Point: 450°F

Shelf Life: 2–3 years

Palm oil, like coconut oil, is semi-solid at room temperature. It is extracted from the pulp of the oil palm fruit, while palm kernel oil is extracted from the fruit’s seed, making it a different oil altogether. Palm oil is known for its health benefits and tastes much like carrot or pumpkin. Nut butters, baked goods, protein bars, coffee creamers, and margarine usually contain palm oil, and it’s a popular cooking oil for curries and spicy dishes.

Keep in mind that palm oil is a vegetable oil, and most vegetable oils are refined and processed, which renders them less flavorful and lower in nutrients. It is more susceptible to rancidity too.

Lisa Howard, author of The Big Book of Healthy Cooking Oils, writes the following about vegetable oils: "Processed oils have been pushed past their heat tolerance and have become rancid in the processing." This includes palm oil, whose production is also associated with land degradation.

Palm oil is another controversial oil that requires you to judge what features are most important. While palm oil has a list of health benefits, know that this doesn’t hold up in commercially packaged foods. Remember, how you use an oil changes its structure and nutrient value. Palm oil is also not an environmentally sustainable choice.

Avocado Oil

Fatty Acid Content: 12% saturated fat, 13% polyunsaturated fat, 71% monounsaturated fat

Smoke Point: 520°F

Shelf Life: Up to 1 year, refrigerated

Avocado oil is more expensive than other oils, but for good reason. It's creamy like an avocado because it's pressed from the fatty inner fruit. It's also virtually tasteless, making it a highly versatile oil suitable for many cooking escapades. Cold-pressed versions are unrefined and have a much higher smoke point than olive oil so it's an ideal oil to cook with. Its fatty acid profile and calorie count are very similar to olive oil, though it contains less vitamin E. Avocado oil is also used topically for skin-care.


QUICK FACT: Avocado oil & B12 cream applied topically may help treat psoriasis, a skin condition. 


Flaxseed Oil (a.k.a Linseed Oil)

Fatty Acid Content: 9% saturated fat, 68% polyunsaturated fat, 18% monounsaturated fat

Smoke Point: 437°F

Shelf Life: 1 month for unrefined versions

Flaxseed oil is extracted from pressing dry, ripe flaxseeds. Like most oils, refined versions may include heat and a chemical solvent. The extraction also removes the beneficial fiber component of the flaxseed, making it less nutritious than the seed itself. Some experts say that it can improve digestion and aid constipation. Although it has a moderately high smoke point, if you try cooking with it you'll discover that it doesn't have the most enchanting scent or flavor. For that reason, we suggest using it sparingly in raw form, such as drizzled over salads or inside smoothies. If you want to reap the health benefits of the flaxseed, best to eat the seed itself, ground just before consumption. 

Sesame Oil

Fatty Acid Content: 14% saturated fat, 42% polyunsaturated fat, 40% monounsaturated fat

Smoke Point: 410°F

Shelf Life: 6 months

Sesame oil is packed with antioxidants and is a strong anti-inflammatory. It’s also used as a massage oil in traditional Ayurvedic treatments. But is this an oil you want to consume regularly? Well, it depends. Taste-wise, it is deliciously nutty, rich, and distinct. Cold-pressed versions make excellent salad dressings and vinaigrettes, while toasting sesame oil releases its exceptional flavor into Asian stir fries and sauces. But it’s high in omega-6 polyunsaturated fat, which isn’t a bad thing, but so is the standard American diet. Too much omega 6 may counteract the benefits of omega 3. If processed and packaged foods comprise a good portion of your diet, consume sesame oil in moderation. Or better yet, ditch the processed foods and choose more natural, wholesome varieties of dietary fat

Walnut Oil

Fatty Acid Content: 9% saturated fat, 63% polyunsaturated fat, 23% monounsaturated fat

Smoke Point: 320°F

Shelf Life: 1–2 months

Walnut oil is better consumed raw because it has a low smoke point. It also becomes slightly bitter once cooked. Its intense nutty flavor is no surprise, given that it’s made by crushing whole, raw almonds to a thick paste then extracting the oil from the solids. Walnuts are rich in the omega-3 fatty acid ALA, which contains anti-inflammatory properties.

Walnut oil really shines as a salad dressing or drizzled over top of a variety of dishes to enhance the appearance and presentation. It may keep for as long as 12 months when stored in a dark, cool place, but we recommend using it within a couple of months after opening.

The Finishing Touch

Here’s a little breakdown of key takeaways from this guide:

Healthiest oils for cooking: Coconut, olive oil, and avocado oil. All three have a high smoke point and are rich in saturated fatty acids.

Best oils for dressings and marinades: Sesame oil and walnut oil. Both have an intense, nutty flavor that cooking destroys, so they’re best eaten raw.

Best oil for essential omega-3 fatty acids: Walnut oil. Walnuts contain nearly 5 times the recommended daily intake of omega 3s.

The shelf life of oil varies greatly depending on oil type, storage conditions, and processing. Unrefined versions go rancid more quickly because they’re more prone to oxidation. Store your oils close to refrigerator temperature in their original dark, glass bottle.

Priority Chef: Quality You Can Trust

At Priority Chef, we think that food prep and cooking should be a fun and rewarding endeavor, but that's only possible with the right tools. That's why we're focused on creating functional, high-quality kitchenware that you and your family will rely on for years.

We design, source, craft, and rigorously test each of our products to ensure the highest quality and convenience. We guarantee (based on experience) that a Priority Chef French Butter Keeper will keep your butter fresh and ready for pastry making endeavors.

From our family to yours, happy leafing about through your local farmer's market for the freshest and most nutrient-dense leafy greens!

References

  1. Health implications of high dietary omega-6 polyunsaturated Fatty acids

  2. Heated vegetable oils and cardiovascular disease risk factors

  3. The Stability and Shelf Life of Fats and Oils

  4. HEALTH EFFECTS OF OXIDIZED HEATED OILS

  5. Everything you need to know about rice bran oil | The Times of India

Resources

How Industrial Seed Oils Are Making Us Sick

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