Helpful Guide to Cooking Oils
Unless you enjoy washing up sticky pans with caked-on food, you’ve probably used cooking oil before. Most people always have some sort of cooking oil in their kitchen – typically olive oil, vegetable oil or sunflower oil – but there’s a whole range of different cooking oils out there, each with their own unique smoke points, flavor profiles and health benefits. In this helpful guide to cooking oils, we’ll take a look at the different types of oils and what they can be used for.
Refined vs Unrefined Oils
After extraction, oils can either be bottled straight away, or refined and processed further. Oils bottled immediately in their natural state are labelled as unrefined, or sometimes as cold-pressed, raw or virgin. Unrefined oils tend to retain their flavors, as well as beneficial minerals, nutrients, and enzymes. However, they have lower smoke points, and can turn rancid if left on the shelf for longer periods of time. Unrefined oils are best for very low heat cooking, or used raw, like in dressings and salads or as a finishing oil.
Refined oils are processed further through filtering, bleaching, or heating. These processes are applied to remove the volatile compounds that break down in virgin oils. Refined oils tend to have a more neutral taste, alongside a higher smoke point and better shelf life.
Neutral Oils vs Flavorsome Oils
Different oils can have wildly different flavor profiles. Neutral oils, like peanut, vegetable, canola, safflower, and corn oils, have a neutral flavor, which will not muddle the flavor profile of your dish. Neutral oils tend to be refined, and therefore typically have higher smoke points too.
Flavorsome oils, on the other hand, can have distinct flavors. Walnut, coconut, and hemp seed oils have strong, savory flavors for example, and the flavor of toasted sesame oil is essential to many Asian dishes. It’s often worth experimenting with these non-neutral oils in salads or low heat dishes to see what works best for you!
Saturated vs Unsaturated Fats
Although consuming too much fat is unhealthy, it is essential to consume some fat to keep your body healthy. The fats you eat give your body energy, and fat also keeps your skin and hair healthy, and insulates your body to keep you warm. Fat also helps you absorb vitamins A, D, E, and K, the so-called fat-soluble vitamins.[1]
Linoleic and linolenic acids are essential fatty acids that our bodies can’t make themselves, so we need to get from food or oils instead. They are necessary for brain development, controlling inflammation, and blood clotting.[2]
There are actually two main types of fat found in cooking oils: saturated fats and unsaturated fats. Saturated fats are typically found in meats, cheeses, butter, and processed foods. Saturated fats should be consumed sparingly, as they are less healthy than unsaturated fats.[3] This is due to their higher concentration of low-density lipoprotein (LDL) cholesterol – the bad kind!
Unsaturated fats, typically found in nuts and seeds, have more high-density lipoprotein (HDL) cholesterol, which is better for your body.[4] They have at least one double bond link between the carbon atoms, which enables unsaturated fats to bend so the molecule is not as saturated with hydrogen as it can be.[5] Monounsaturated fatty acids, also known as oleic acid, have just one double bond, while polyunsaturated fatty acids have more than one double bond. Monounsaturated fatty acids have a zig-zagging molecular shape rather than being straight, and are slightly more stable than the polyunsaturated acids found in vegetable oils.[6]
A general rule of thumb is that if an oil is liquid at room temperature, it contains more unsaturated fats, making them healthier overall than things like butter or lard, which are solid at room temperature and therefore contain more saturated fats.
Omegas
Within unsaturated fats, we find omegas. Omega-3 and omega-6 fatty acids are both polyunsaturated fatty acids, and omega-9 fatty acids are typically monounsaturated fatty acids. The numbers represent how many carbons away from the methyl end of the fatty acid chain hat the first double bond of carbon appears: if it’s three carbon molecules away, it’s an omega-3 fatty acid, six away is an omega-6 and nine is omega-9.[7] Simple!
Omega-3
Omega-3 fatty acids can be found in plants and meats, and benefit heart health. The essential fatty acid alpha-linolenic acid (ALA) is a form of omega-3 found in plants, such as in flaxseed, chia seed, walnuts, canola and soybean oils. Our bodies can’t make ALA, so we need to obtain it from our diet.
Omega-6
Linoleic acid is another essential fatty acid that our bodies can’t make themselves. Linoleic acid is an omega-6 fatty acid, and can be found in vegetable oils, nuts and seeds.[8] According to fatty acids expert Dr. Bill Harris:
“Both the omega-3 and omega-6 fatty acids are considered ‘partners in prevention’ as it relates to heart disease. So all [polyunsaturated fatty acids] are ‘good fats’.”[9]
However, omega-6 can be harmful if consumed in excess, as it can promote inflammation – good in small doses, such as if you need to heal from a cut, but long-term chronic inflammation can trigger heart disease, diabetes and cancer.
Omega-9
Unlike omega-3s and -6s, omega-9 fatty acids tend to be monounsaturated. Omega-9 fatty acids are nonessential, as they can be made in the body. However, it is still healthy to consume some omega-9 fatty acids, from sources such as canola and olive oils, and almond oil.[10]
What is a Smoke Point?
The smoke point, or burning point, of an oil is the temperature at which the oil stops shimmering and begins to smoke. Different cooking oils have a wide range of smoke points, from a low 325 degrees Fahrenheit to a very high 520 degrees.
It’s important to be aware that the smoke point is not a bad thing – in some cases, such as stir-frying in a very hot wok, reaching the smoke point of your oil is inevitable.
However, reaching the smoke point is typically a sign that your oil is breaking down. This can release burnt- or bitter-tasting chemicals into your food, which isn’t particularly pleasant. There is also the potential of releasing free radicals into your food, which are not good for your body.[11]
It’s always worth double-checking the smoke point of your oil before cooking to make sure that your choice is suitable and that the oil can handle the heat!
Different Types of Oil
[oil lineup]
[alt text: an infographic of the different cooking oils discussed below]
So now we know all about the characteristics that make up a cooking oil – refined or unrefined; neutral or flavorsome; saturated, mono-, or polyunsaturated; high or low smoke point. Let’s check out the characteristics of a range of the most popular cooking oils in America.
Almond oil
Almond oil can be found refined or cold-pressed. It is full of monounsaturated fats, and can help to elevate levels of high-density lipoproteins, or ‘good’ cholesterol, in your body.
Best for:
Refined almond oil is perfect for sautéing and roasting. Cold-pressed almond oil has a mild, nutty flavor, and is best saved for cold dishes and drizzling over salads in a dressing or as a finishing oil. If you’ve got nut allergies, it would be best to avoid almond oil.
Avocado oil
Avocado oil is pressed from fresh avocado pulp, which is comprised of up to 25% fat. It is comprised of almost 70% oleic acid, a monounsaturated omega-9 fatty acid.[12] It is less prone to oxidation than polyunsaturated oils and remains liquid at room temperature. It is high in vitamin E antioxidants which have anti-inflammatory properties, and also contains lutein, which is good for your vision.[13] This makes avocado one of the top healthiest oils.
Avocado oil has the highest smoke point of all plant-based cooking oils, at 510 to 520 degrees Fahrenheit.
Best for:
Avocado oil can be used for sautéing and frying but is most healthy when used raw and cold-pressed in sauces and salad dressings, as its fats will break down when cooking.
Coconut oil
Extracted from coconut flesh, coconut oil is available in virgin and refined options. Refined coconut oil tastes fairly neutral, while extra virgin has a more distinctly coconutty taste. Coconut oil is solid at room temperature and has a low smoke point of 350 degrees Fahrenheit.
Coconut oil is one of the top healthiest oils, as it contains unsaturated fatty acids, which are easier to digest than other oils. This means that these fats can be converted to energy more easily, which can boost metabolism, and is good for HDL cholesterol. There is also some evidence that coconut oil can help protect your brain health.[14]
Best for:
Coconut oil works really well for frying and sautéing and can be swapped out for butter when baking. It’s also a staple for cooking Thai and Indian food. However, it’s no good for vinaigrettes and marinades as it’s solid at room temperature!
Corn oil, vegetable oil, canola oil
Corn oil, vegetable oil, and canola oil are all different names that generally describe the same thing. They also contain good amounts of ALA, an essential omega-3 fatty acid. Canola oil has a near even ration of omega-6 to omega-3. Avocado oil is a healthier alternative, but comes at a higher price.
With a neutral flavor and smoke points between 400 and 450 degrees Fahrenheit, these oils are best for frying and deep frying.
Best for:
Corn oil, vegetable oil and canola oil are best for frying and deep-frying.
Flaxseed oil
Also known as linseed oil or flax oil, flaxseed oil is made from ground and pressed flaxseeds. This process releases their natural oil, which has a nutty flavor and a low smoke point of 225 degrees Fahrenheit. As such, it should not be used for cooking, and best taken as a supplement or added to dips and dressings. Flaxseed oil should also be stored in the refrigerator.
Flaxseed oil is one of the top healthiest oils, as it has the highest alpha-linolenic acid (ALA) omega-3 content of all oils – great for overall heart health.[15]
Best for:
Flaxseed oil is great as a finishing oil for dips and dressings, and you can drizzle a teaspoon or so into a morning smoothie to boost your nutrition too.
Ghee
Originating from India, ghee is traditionally used as a cooking oil in Ayurveda culture.[16] Ghee is a class of clarified butter, made by melting butter to separate it into liquid fats and milk solids, then removing the milk solids. This means that ghee has less lactose than butter but is composed almost entirely of fat – so use it in moderation.[17]
Ghee has a deep nutty flavor, and is good for dairy-intolerant people, as well as being a great source of fat-soluble vitamins A, D, E and K.
Best for:
Ghee is best for sautéing, roasting, and baking, and is great for curries too.
Grapeseed oil
A byproduct of winemaking, grapeseed oil is a versatile, neutral-flavored oil with a medium-high smoke point of 390 degrees Fahrenheit.[18]
Grapeseed is one of the top healthiest oils, high in vitamin E and antioxidants. Studies have shown that consuming grapeseed oil can improve the body’s insulin resistance.[19] The best health benefits come from cold- or expeller-pressed grapeseed.
Best for:
Grapeseed oil can be used for sautéing and frying, or raw in dressings.
Hemp seed oil
A striking dark green color, hemp seed oil has a rich, nutty flavor. It is too sensitive to heat and should be stored in the refrigerator.
Best for:
Hemp seed oil is best used as a finishing oil for soups and salads, or in marinades, dressings, or combined with a neutral oil for vinaigrettes.
Olive oil
Olive oil is made from pressing fresh olives and can range in color from golden to dark green.
Olive oil is one of the top healthiest cooking oils, due to its high monounsaturated fats and omega-9 fatty acids content.
Extra virgin (EVOO)
Extra virgin olive oil is made by grinding and pressing olives, with no other chemicals, heat or further processing. This results in a lower yield, so the final product is more expensive than refined olive oil. However, this cold-pressing process also maintains antioxidants and good monounsaturated fats. Extra virgin olive oil also contains vitamins A, D, E and K, alongside beta-carotene.[20]
Extra virgin olive oil tends to be darker in color than refined oils, typically between a golden yellow and a dark green. Extra virgin olive oils have a robust and complex flavor profile, often with a distinctly olive-y flavor, and sometimes have nutty, peppery, or spicy notes too depending on the olives pressed. Still-green olives contribute a spicy or peppery flavor, whilst mature olives tend to be sweeter.
Best for:
Extra virgin olive oil is expensive and has a low smoke point of 325 to 375 degrees Fahrenheit, so there’s no reason to use it for cooking with. Save it for salad dressings and sauces or use it as a finishing or dipping oil.
Light (pure)
You might be surprised to find out that light olive oil does not contain fewer calories or fat than extra virgin olive oil. In fact, ‘light’ refers to the lighter color and more neutral flavor of this refined oil. Light olive oil is produced by heating the virgin oil produced after a first pressing of olives. This gives the oil a golden hue, longer shelf life and higher smoke point – 465 to 470 degrees Fahrenheit – compared to EVOO. However, the heat-pressing also leads to fewer nutrients and a more neutral flavor.
Best for:
Due to the more neutral flavor and higher smoke point compared to EVOO, light olive oil is more suited to sautéing, roasting and other high-heat cooking than finishing.
Palm oil
Palm oil comes from palm trees native to Africa. Although it has been used for thousands of years, the modern production methods for palm oil are causing a huge environmental impact through deforestation and the destruction of animal habitat. In fact, the World Wildlife Fund estimates that every hour, an area of around 300 football fields in tropical forests is cleared in order to produce palm oil.[21]
Like coconut oil, palm oil is semi-solid at room temperature. It is often used for sautéing or frying due to its high smoke point of 450 degrees Fahrenheit.
Best for:
Alongside being used a lot in a huge range of products from pizza dough to lipstick and chocolate to laundry detergent, palm oil is best used for curries and other spicy dishes.
Peanut oil
Peanut oil is made from pressed steam-cooked peanuts, and is widely used in Asian cuisines. It has a mild nutty flavor and a high smoke point around 450 to 475 degrees Fahrenheit, making it great for deep-frying and other hotter cooking methods.
Peanut oil is comprised mostly of monounsaturated fatty acids, which lower bad cholesterol and raise good cholesterol, and is also fairly high in omega-6.
Best for:
Alongside being great for frying, deep-frying, and other hotter cooking methods, you can use peanut oil for roasting and grilling. If you’ve got nut allergies, it would be best to avoid peanut oil.
Safflower oil
Safflower oil has a very mild, virtually undetectable flavor, making it ideal for many recipes. It also has a high smoke point, between 440 and 520 degrees. It has a high polyunsaturated fat content – high enough that it remains a liquid even when refrigerated.[22]
Best for:
Safflower oil is perfect for baking and frying, and can be used raw as a dressing and in other cold food preparation too. You can also get high oleic versions of safflower oil, which have more monounsaturated fats and a higher smoke point, so is better suited to high-heat applications such as deep-frying.
Sesame oil
Sesame oil is a great all-purpose oil, with a neutral flavor and high smoke point at 410 degrees Fahrenheit.
A single tablespoon of sesame oil contains 2 percent of your recommended daily vitamin K intake – good for bone support and blood clotting.[23]
Best for:
Sesame oil is best for Asian, Mediterranean, and Middle Eastern foods. If you want flavor, look no further than toasted sesame oil. It has a deliciously nutty sesame flavor, and tastes amazing drizzled over a stir fry, in marinades, or in Asian salad dressings with ginger and soy sauce.
Sunflower oil
Pressed from seeds of sunflower, sunflower is commonly used as a frying oil due to its high smoke point of 450 degrees Fahrenheit, and has a neutral flavor that won’t overwhelm a dish.
It is particularly high in vitamin E, containing 28 percent of the daily recommended intake in just a tablespoon![24]
Best for:
A good all-rounder, sunflower oil is great for baking and frying, and can also work nicely in salad dressings.
Walnut oil
The delicate and nutty walnut oil has a big flavor – use it sparingly! It has a low smoke point at 320 degrees Fahrenheit, so should not be used for cooking.
Best for:
Walnut oil is perfect as a finishing oil, or in marinades and dressings. Drizzling a small amount into soups and salads will taste delicious. If you’ve got nut allergies, it would be best to avoid walnut oil.
Summary
So now you know all about the different types of oils: their flavor profiles, smoke points, health benefits and best uses. It can be a lot of fun experimenting with different types of oils to see what flavors work best with different dishes, or trying out new cooking methods with oils with different smoke points. Perhaps next time you’re at the supermarket, rather than reaching for your familiar olive or sunflower oil, you could try out something new!
FAQs
Q: What’s the best place to store my cooking oils?
A: In most cases, oils are best stored in cool, dry and dark environments – a cupboard is perfect. Some raw oils are better stored in the refrigerator, so just check the packaging on fancier oils. If you’re trying to work out how to store everything in your kitchen, this helpful guide to kitchen organization could help you out.
Q: My expensive extra-virgin olive oil tastes funny. Why?
A: If you’ve got a bottle of extra-virgin olive oil that’s been open for some time, it will start to go off – even if it’s top-quality stuff. This is due to a process called oxidation, which also negatively impacts the health benefits of your oils.
This is actually the case for many raw oils: just like the nuts or fruits from which the oil is extracted, the oil itself has a shelf life. Extra virgin olive oil is usually good for 3 to 6 months after opening.
If you’ve consumed rancid oil, don’t worry – it won’t make you sick, but will almost certainly have an undesired effect on the flavor profiles of your dishes. If your oil tastes bitter, stale, sour or rancid in any way, it’s probably past its best.
References
[1] David C. Dugdale, III (13 July 2020), ‘Dietary fats explained’. Accessed at: https://medlineplus.gov/ency/patientinstructions/000104.htm.
[2] David C. Dugdale, III (13 July 2020), ‘Dietary fats explained’. Accessed at: https://medlineplus.gov/ency/patientinstructions/000104.htm.
[3] David C. Dugdale, III (13 July 2020), ‘Dietary fats explained’. Accessed at: https://medlineplus.gov/ency/patientinstructions/000104.htm.
[4] David C. Dugdale, III (13 July 2020), ‘Dietary fats explained’. Accessed at: https://medlineplus.gov/ency/patientinstructions/000104.htm.
[5] Alyssa Pike, RD (30 July 2020), ‘Oh My Omega: The Difference Between Omega-3, 6, and 9’. Accessed at: https://foodinsight.org/oh-my-omega-the-difference-between-omega-3-6-and-9/.
[6] Alyssa Pike, RD (30 July 2020), ‘Oh My Omega: The Difference Between Omega-3, 6, and 9’. Accessed at: https://foodinsight.org/oh-my-omega-the-difference-between-omega-3-6-and-9/.
[7] Alyssa Pike, RD (30 July 2020), ‘Oh My Omega: The Difference Between Omega-3, 6, and 9’. Accessed at: https://foodinsight.org/oh-my-omega-the-difference-between-omega-3-6-and-9/.
[8] Alyssa Pike, RD (30 July 2020), ‘Oh My Omega: The Difference Between Omega-3, 6, and 9’. Accessed at: https://foodinsight.org/oh-my-omega-the-difference-between-omega-3-6-and-9/.
[9] Alyssa Pike, RD (30 July 2020), ‘Oh My Omega: The Difference Between Omega-3, 6, and 9’. Accessed at: https://foodinsight.org/oh-my-omega-the-difference-between-omega-3-6-and-9/.
[10] Alyssa Pike, RD (30 July 2020), ‘Oh My Omega: The Difference Between Omega-3, 6, and 9’. Accessed at: https://foodinsight.org/oh-my-omega-the-difference-between-omega-3-6-and-9/.
[11] Rekhadevi Perumalla Venkata and Rajagopal Subramanyam (2016), ‘Evaluation of the deleterious health effects of consumption of repeatedly heated vegetable oil’. Accessed at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5616019/.
[12] Hrefna Palsdottir, MS (6 April 2016), ‘9 Evidence-Based Health Benefits of Avocado Oil’. Accessed at: https://drive.google.com/file/d/1YfYSXRwNcOiFQiFWYJpGHhhgu75eMZWr/view?usp=sharing.
[13] Ofelia B. O. Ashton, Marie Wong, Tony K. McGhie, Rosheila Vather, Yan Wang, Cecilia Requejo-Jackman, Padmaja Ramankutty, Allan B. Woolf (27 December 2006), ‘Pigments in avocado tissue and oil’. Accessed at: https://pubmed.ncbi.nlm.nih.gov/17177553/.
[14] Monica Reinagel (15 September 2016), ‘Can coconut oil treat or prevent Alzheimer’s disease? What are the benefits of coconut oil and MCTs for brain health?’. Accessed at: https://www.scientificamerican.com/article/is-coconut-oil-good-for-brain-health/.
[15] Harvard Health Publishing (29 July 2019), ‘Why not flaxseed oil?’. Accessed at: https://www.health.harvard.edu/heart-health/why-not-flaxseed-oil.
[16] Vrinda Devani, MD, AP (4 September 2018), ‘Ghee—Everything You Need to Know about Clarified Butter’. Accessed at: https://www.banyanbotanicals.com/info/blog-the-banyan-insight/details/ghee-the-golden-nectar-of-ayurveda/.
[17] Dan Brennan, MD (30 September 2020), ‘Ghee: Is It Good For You?’. Accessed at: https://www.webmd.com/diet/ghee-good-for-you#1.
[18] Mariah Adcox (12 July 2017), ‘The health and beauty benefits of grapeseed oil’. Accessed at: https://www.medicalnewstoday.com/articles/318395.
[19] Pardis Irandoost, Mehrangiz Ebrahimi-Mameghani, Saeed Pirouzpanah (19 March 2013), ‘Does grape seed oil improve inflammation and insulin resistance in overweight or obese women?’. Accessed at: https://pubmed.ncbi.nlm.nih.gov/23506314/.
[20] International Olive Council (date unknown), ‘The Antioxidant Properties of the Olive Oil’. Accessed at: https://www.internationaloliveoil.org/olive-world/olive-oil-health/#antioxidant.
[21] Jodi Helmer (9 January 2017), ‘The Perils of Palm Oil: How a Popular Product Leads to Deforestation’. Accessed at: https://www.fix.com/blog/how-palm-oil-affects-the-environment/.
[22] Elea Carey (15 December 2016), ‘Safflower Oil: A Healthier Cooking Oil’. Accessed at: https://www.healthline.com/health/safflower-oil-healthy-cooking-oil.
[23] Erica Kannall (date unknown), ‘Is Sesame Oil Healthy?’. Accessed at: https://healthyeating.sfgate.com/sesame-oil-healthy-7524.html.
[24] Michael Joseph (26 June 2019), ‘Is Sunflower Oil Healthy?’. Accessed at: https://www.nutritionadvance.com/is-sunflower-oil-healthy/.
