Smoking Oil In A Pan: What Does It Look Like?

When cooking with oil, it's important to be aware of its smoke point – the temperature at which it starts to burn and produce smoke. Different oils have different smoke points, and exceeding this temperature can negatively impact the flavour of your food and release harmful chemicals. For example, extra-virgin olive oil has a smoke point of around 350°F, while avocado oil can reach up to 520°F. Heating a pan with nothing in it can also produce smoke, but this is not necessarily toxic.

Different oils have different smoke points

In general, the more refined an oil is, the higher its smoke point. A higher smoke point gives an oil a wider range of uses because you can use it at higher temperatures to fry, grill, deep-fry, and more. The refined oils most recommended for high-heat cooking, grilling, and deep-frying are “high oleic”, which means they are high in monounsaturated fats. Some oils, like olive oil, are naturally high in monounsaturated fat but also high in polyunsaturated fats, which makes them less stable for super-high-heat cooking and long-term storage.

Unrefined oils, on the other hand, are extracted and then simply filtered to remove impurities. This means they retain much more of their nutritional value but they aren’t as stable. Because they are minimally processed, these oils taste much more like the plants they come from, which can be a positive or a negative, depending on the dish. The unrefined culinary oil options in mainstream grocery stores have increased over time. Examples include avocado, grapeseed, sesame, hemp seed, flaxseed, pumpkin seed, and walnut oil.

The smoke point for some unrefined oils like flaxseed, wheat germ, and walnut oil is low (around 225°F) and many experts say we shouldn’t heat them at all. They are rich in polyunsaturated fats and are best used in smoothies, drizzles, salad dressings, etc.

Unrefined oils that are higher in monounsaturated fats, like extra virgin olive oil, are considered medium smoke point oils. This means you can use them for most cooking on the average home stove, including sautéing and pan-frying, slow-roasting in the oven, and even stir-frying as long as the heat doesn’t exceed about 375°F.

Naturally refined oils like coconut, grapeseed, and sunflower have much higher smoke points, ranging between 400-500°F.

• Avocado oil (refined): 480-520°F
• Safflower oil: 450-500°F
• Canola oil: 400-475°F
• Sunflower oil (refined): 450°F
• Peanut oil (refined): 450°F
• Coconut oil (refined): 400-450°F
• Grapeseed oil: 390-420°F
• Sesame oil (refined): 410°F
• Macadamia oil: 400°F
• Extra virgin olive oil (unrefined): 325-400°F
• Avocado oil (unrefined): 350-400°F
• Vegetable oil: 400°F
• Unrefined coconut oil: 350-380°F
• Sesame oil (unrefined): 350°F
• Sunflower oil (unrefined): 320°F
• Peanut oil (unrefined): 320°F
• Walnut oil (unrefined): 320°F
• Hemp Seed oil: 300-330°F
• Almond oil (unrefined): 225°F
• Flax seed oil (unrefined): 225°F

The dial on the stove controls heat, not temperature

When cooking with oil, it's important to understand the smoke point: the temperature at which oil stops shimmering and starts smoking. Different oils have different smoke points, so it's crucial to choose an oil with a suitable smoke point for your cooking method. For instance, select an oil with a smoke point above 400°F for high-temperature cooking techniques like searing and stir-frying.

The dial on your stove controls the heat output, not the temperature. This means that the higher the setting, the faster your pan will heat up. However, the eventual temperature reached will depend on various factors, including the pan's material and thickness, the type of stove, and the presence of food in the pan. Therefore, it's essential to monitor the oil's behaviour and adjust the heat accordingly to prevent smoking.

To prevent your oil from smoking, choose the appropriate heat setting for your desired cooking temperature. For instance, a medium-low setting is suitable for sweating onions, while a medium setting is ideal for cooking vegetables like onions and broccoli. Additionally, consider the type of pan you're using. Lighter pans, such as those made of cast iron, may heat up faster and cause oil to smoke sooner.

If your oil does start smoking, don't panic. Remove it from the heat, especially if it's a flavorful oil, as continued heating can lead to degradation and the release of undesirable substances. Allow the oil to cool, then assess its taste and smell. If it has developed unpalatable flavours, discard it and start with a fresh batch.

Oils with high fatty acid content have lower smoke points

When choosing a fat or oil to cook with, the most important temperature to consider is the smoke point. The smoke point is the temperature at which the oil starts to smoke, which it will reach before its boiling point. Different oils have different smoke points, and the smoke point of an oil depends on its components, origin, and level of refinement. The smoke point tends to increase as the free fatty acid content decreases and the level of refinement increases.

Refined oils have higher smoke points because the refining process removes impurities and free fatty acids that can cause oils to smoke. Oils high in polyunsaturated fats, such as sunflower, flaxseed, or safflower, tend to have lower smoke points. Oils higher in monounsaturated fats, including avocado, canola, and olive, have medium smoke points. Oils high in saturated fats, such as coconut and palm oils, are high smoke point oils.

It is important to choose an oil with a high smoke point when frying foods. Most foods are fried at temperatures between 350°F and 450°F, so it is best to choose an oil with a smoke point above 400°F. Fats and oils with lower smoke points, like butter and olive oil, are better suited for lower-temperature cooking methods such as sautéing.

Reheating oil can create carcinogenic compounds

The health risks of reheated oil are twofold: inhalation of cooking fumes and the consumption of the oil itself. The carcinogenic compounds produced by reheated oil have been linked to an increased incidence of genotoxic, mutagenic, and tumorogenic effects, as well as various cancers, including lung, colorectal, breast, and prostate cancers.

Additionally, the repeated heating of oil can cause it to react with atmospheric air, producing highly oxidized compounds that may be highly toxic and carcinogenic. These compounds can also have detrimental effects on the oil's nutritional properties, such as its fatty acids, vitamins, and natural antioxidants.

To avoid the potential health risks associated with reheating oil, it is recommended to use oil only once and not to heat it past its smoke point. Different oils have different smoke points, so it is important to choose an oil with a high enough smoke point for the intended cooking method. For example, a neutral oil with a high smoke point, like peanut or safflower oil, is best for stir-frying, as this cooking method requires a very high temperature.

Avocado oil has one of the highest smoke points

When cooking with oil, it's important to know its smoke point—the temperature at which it starts to smoke and break down, giving off a serious amount of smoke. If your oil starts smoking, that means it's too hot. Different oils have different smoke points, and some pans conduct heat differently, so it's important to be mindful of the combination you're using.

Avocado oil is also high in monounsaturated fat, which is considered a "good" or "healthy" fat. It's recommended to store it in a cool, dark place, away from direct heat or sunlight. Keep it tightly sealed, and if it comes in a translucent bottle, consider wrapping it in tin foil to extend its shelf life.

When cooking with avocado oil, or any oil for that matter, be mindful of the type of pan you're using. Some pans, like cast iron, may cause the oil to smoke faster due to uneven heat distribution. Additionally, be cautious when reusing oil, as hitting the smoke point lowers the smoke point even further. If your oil has been smoking, it won't be suitable for reuse.

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