Cooking Oils and Fats: A Complete Guide

What are Fats and Oils?

Animal fats and plant oils can add a lot of flavor to food and make it more appealing. However, that doesn’t mean you should indiscriminately add them to your dishes.

Fats and oils make up a class of macronutrients called lipids. Each type of lipid carries a different set of physical properties, flavors, and nutrition profile.

Certain oils stand up better to high-heat cooking methods. Meanwhile, we prize other fats for their distinct qualities such as flavor and aroma.

We must consider many factors to decide which oils are healthiest and work best for a particular cooking method.

This guide will outline lipid qualities to help you choose the best oil to use.

*We will use the terms lipids, fats, and oil interchangeably. The most common distinction is that fats are solid at room temperature, while oils are liquid.

Smoke Point

An oil’s or fat’s smoke point refers to what temperature it will start to smoke. When you heat oil beyond its smoke point, it changes the flavor and health profile.

The smoke point varies between types of oil. Even within the same oil types, smoke points vary based on impurities and free fatty acids.^[1]

When you smoke oil, it’ll become darker and release wisps of smoke. If you were to taste it (don’t!), you may also pick up an unpleasant burnt/smoky taste.

However, invisible changes also occur in smoked oils. The oil begins to oxidize,^[2] a process which destroys its antioxidants. Antioxidants protect the oil from free radicals, which form from exposure to light and heat.

Free radicals not only further degrade the oil quality but can also cause oxidative stress in your body.^[3] These compounds wreak havoc on your cells, which can potentially lead to inflammation, heart disease, and cancer.^[4]

Therefore, you should never heat oils beyond their smoke point. You may also wish to choose different oils depending on your desired cooking temperature.

Generally, you want high smoke points for high-heat cooking, such as searing, deep-frying, and pan-frying. You could use avocado oil, grapeseed oil, coconut oil, tallow, or lard for high heat cooking.

Reserve the oils with low smoke points for dips, salads, and emulsifying sauces. You could drizzle olive oil, sesame oil, and butter onto foods or use them for low-heat cooking.

Smoke Point Chart

Oil	Smoke Point °F	Smoke Point °C
Refined Avocado Oil	520°F	270°C
Safflower Oil	510°F	265°C
Rice Bran Oil	490°F	254°C
Refined or Light Olive Oil	465°F	240°C
Soybean Oil	450°F	232°C
Peanut Oil	450°F	232°C
Ghee or Clarified Butter	450°F	232°C
Corn Oil	450°F	232°C
Refined Coconut Oil	450°F	232°C
Safflower Oil	440°F	227°C
Refined Sesame Oil	410°F	210°C
Vegetable Oil	400-450°F	204-232°C
Beef Tallow	400°F	204°C
Canola Oil	400°F	204°C
Grapeseed Oil	390°F	199°C
Unrefined or Virgin Avocado Oil	375°F	190°C
Pork Fat or Lard	370°F	188°C
Chicken Fat or Schmaltz	375°F	190°C
Duck Fat	375°F	190°C
Vegetable Shortening	360°F	182°C
Unrefined Sesame Oil	350°F	177°C
Extra Virgin or Unrefined Coconut Oil	350°F	177°C
Extra Virgin Olive Oil	325-375°F	163-190°C
Butter	302°F	150°C

Oil Smoke Points^{^[5]}

Flavor

Oils tend to dissolve fat-soluble compounds, which gives them extra flavor. This distinct quality allows you to either create flavored oils or mask other flavors.

An oil’s flavor profile may ultimately determine how you use it or what recipes work well with it.

Oil Flavors and Commonly Associated Cuisines

Oil	Flavor	Uses
Avocado Oil	Neutral	Versatile
Butter	‘Buttery,’ dairy-like	Versatile
Coconut Oil	Coconut	Desserts, Southeast Asian cuisine
Ghee	Intensely buttery, without dairy	Indian, Middle Eastern, Southeast Asian cuisine
Extra Virgin Olive Oil	Earthy	Mediterranean cuisine
Sesame Oil	Nutty	Asian cuisine

Oil Flavor and Associated Cuisines

You could make a spice-infused oil by lightly toasting the spices with a neutral oil.

However, you can just as easily extract unwanted flavor compounds from flavorful oils through emulsification. Emulsification is a process to mix oil and water, like with mayonnaise.

Heat may reduce an oil’s taste if desired, although it may slightly change its nutritional qualities, too. Neutralizing the oil means you can use it in any dish without worrying about clashing flavors.

For example, you may want to deep fry with coconut oil because it holds up well against heat.^[6] But you also won’t have to worry about imparting coconut flavor into your foods after it begins to lose flavor.

Refined vs. Unrefined Oils

Unrefined oils are very different from refined oils. Not only do they differ in the extraction process, but they also have entirely different nutritional qualities.

Unrefined oils usually bear the label ‘cold-pressed’ or ‘expeller-pressed. These oils come from sources which are pressed without heat, as the ‘cold-pressed’ suggests.

Refined oils rely on industrial processing techniques, which may introduce potentially toxic chemicals. Processing includes refining, bleaching, and deodorizing oils.^[7]

Refined oils may contain traces of hexane, which manufacturers heat to extract oils from their source.^[8]Hexane is dangerous at high concentrations, but not necessarily at low concentrations.

However, the human body metabolizes hexane into toxic metabolites like 2-5 hexanedione. Chronic exposure to this chemical may cause peripheral polyneuropathy, a type of damage to the nervous system.^[9]

Processed oils may also contain other potentially dangerous chemicals. Some refined oils contain BHA and TBHQ for their antioxidant-potential.^[10]

Studies demonstrate a link between BHA and cancer in animal studies.^[11] Meanwhile, TBHQ causes T-cell suppression, which suppresses the immune system.^[12] T-cells are the immune cells responsible for fighting off dangerous infections (such as coronavirus) and cancer growth.

Fatty Acid Saturation

Saturation is a chemical property that determines the oil or fat’s nutritional and physical properties. It refers to the presence of hydrogen atoms in the lipid’s fatty acid structure.

Saturated Fats

Saturated fats carry the maximum capacity of hydrogen atoms on their fatty acid chains (hence the name, saturation). Saturation gives the fat a linear structure, allowing the fat molecules to condense into a solid at room temperature.

Saturated Fats:

Butter
Coconut oil/milk
Other animal fats

Unsaturated Fats

Unsaturated fats have missing hydrogen atoms, which distorts the appearance and gives them a jagged shape. Due to the non-linear structure, they can’t pack as tightly as their saturated counterparts, preventing them from solidifying at room temperature.

Unsaturated Fats:

Avocado oil
Olive oil
Other liquid oils

Trans Fats

Trans fats are a hybrid of saturated and unsaturated fats. Although missing hydrogen, these fats are linear and can become solid at room temperature.

A majority of trans fats are artificial, making it hard for the body to metabolize. They were popular when health experts recommended reducing saturated fats without evidence.

Trans Fats:

Margarine
Hydrogenated or Partially Hydrogenated Oils
Naturally occurring in small quantities

Health Concerns

Saturated fats have had a bad reputation for supposedly increasing the risk of cardiac disease and death.

However, recent studies find that replacing saturated fat intake with unsaturated fats doesn’t reduce the risk of death from heart disease or any cause.^[13]

Rather than blaming a single macronutrient like saturated fat, it’s wiser to look at your overall nutrition profile.

For example, eating a vegetable curry with coconut milk (which contains saturated fats) hardly compares to eating heavily processed meats loaded with excess salt and sugar.

If there’s any fat to avoid at all costs, it’s hydrogenated/partially hydrogenated oils. There is a widespread ban on these artificial trans fats because they lead to increased inflammation, heart disease, and potentially diabetes.^[14]

Omega-3 vs. Omega-6 Fatty Acids

Omega-3 and omega-6 fatty acids are essential fatty acids. Since our bodies do not synthesize these fatty acids, we must acquire them from our diet.

Omega-3 is alpha-linoleic acid, which is an anti-inflammatory fatty acid. Omega-6 is linoleic acid, which is an inflammatory fatty acid.^[15]

Naturally, our bodies require both inflammation to fight off infections and anti-inflammatories to prevent excessive damage from inflammation.^[16]

As with all things, there needs to be a balance to sustain life. Therefore, it’s essential to get the ratio of omega-3 and omega-6 right.

Currently, our bodies today have an average omega-6 to omega-3 ratio of 16:1. However, reducing the omega-6 to omega-3 ratios to the following has produced health benefits for varying health conditions^[17]:

5:1 – Benefit for asthma patients
3:1 – Decreases inflammation in rheumatoid arthritis patients
2.5:1 – Decreases cancer cell growth colorectal cancer

Omega-3 and Omega-6 Content of Oils

To calculate the ratio, divide omega-6 content by omega-3 content. For example, safflower oil has a ratio of 14:1 (14 parts omega-6 to 1 part omega-3).

Vitamin E

Vitamin E is one of the most common vitamins found in oils. However, there are two forms of vitamin E: alpha-tocopherol and gamma-tocopherol.

Research suggests sticking to the alpha-tocopherol, found in olive oil and sunflower oil. Alpha-tocopherol is an antioxidant, which protects your body from oxidative stress and free radicals.

Gamma-tocopherol is also an antioxidant found in canola, corn, and soybean oils. However, it has different consequences on the body.

Studies have linked gamma-tocopherol concentrations in the body with lower vitamin E intake, higher inflammation, and increased oxidative stress.^[18] Another study associates increased gamma-tocopherol consumption with a higher incidence of lung disease and reduced lung function.^[19]

Oil Storage

Your storage method will affect how long your oil lasts and its nutritional quality. It’s best to minimize your oil’s exposure to open-air, heat, or light.^[20]

These factors can trigger oxidation, causing antioxidants to degrade, which increases free radical concentration and risk of disease.

They may also cause the oil to go rancid. Rancidity refers to the breakdown of fats into free fatty acids. If your oil smells or tastes off (soapy, bitter, metallic), it may be rancid due to the fatty acids.

Therefore, it’s best to store oils in a sealed container in a cool, dark place. Use an opaque or tinted bottle that keeps light and oxygen out.