Anyone can toss some oil into a pan and cook, but if you want to up your cooking game, you need to choose different oils depending on the dish you're making and how you plan to cook it. Using the right one can mean the difference between a tasty, well-cooked meal and a smoke alarm going off over your burned food.
We're not suggesting that you run out and buy a dozen different oils just in case you need them, but there is a definite benefit benefit to having more than one type of cooking oil in your kitchen. Depending on whether you plan to bake, fry or grill, a different oil will yield different results, and give you more control over the cooking time and temperature.
Why Smoke Point Matters
First, a little science. Each different type of oil or fat has its own smoke point, which is the temperature at which it begins to break down, smoke, and start to taste awful. Around that same temperature, the flavour and nutritional value falls off as well. What you're left with isn't very tasty and isn't very good for you.
The chemical process behind this is simple: As you heat a fat of any kind, it begins to break down into free fatty acids and glycerol. As the temperature rises, the glycerol breaks down further and produces a bitter-smelling, acrid chemical called acrolein. It's that acrolein in the smoke that makes your eyes itch, and it's also what makes the food you cook in that overheated oil taste terrible. Acrolein is no good for you either -- too much is toxic, and it irritates the eyes, nose, throat and ears when it is airborne.
This is why it's important to choose the right type of oil for the cooking method and the dish you're going to make. If you plan to fry or grill, you want an oil that will stand up to high heat without breaking down on you. If you're going to use the oven, you have some more flexibility depending on the temperature you set. With the right oil and the right cooking method, you'll taste a noticeable difference in your food.
As you refine these oils, clarify them, or buy higher quality versions, the smoke point increases. For example, clarified butter, or ghee, smokes at a whopping 252°C, making it ideal for high-heat cooking tasks like stir frying.
For Low-Temperature Cooking And Baking
As a rule, unrefined oils, dairy products, and animal fats have the lowest smoke points, and are best suited for lower-temperature cooking processes such as baking, simmering, and low-heat pan frying. Unrefined oils are as close to the natural flavour of the oil as you can get. Here are a few oils in this range best reserved for lower-heat preparation methods, where you actually want to taste the oil or fat you're using:
- Flaxseed Oil: Smokes at approximately 107°C
- Unrefined Walnut Oil: Smokes at approximately 160°C
- Unrefined Olive Oil: Smokes at approximately 160-162°C
- Butter or Lard: Smokes at approximately 176-190°C
Photo by Nicholas Humfrey
For Medium-Heat Cooking And Frying
Most of your middle-of-the-road oils have applications in low-heat and cold preparations, but can also be used on the stovetop or in the oven. Refined oils -- the kind you'll find in most supermarkets -- fit in this category, along with some all-purpose oils that you may already have. For example:
- Coconut Oil: Smokes at approximately 176°C
- Extra Virgin, High-Quality Olive Oil: Smokes at approximately 375-400°F/190-204°C
- Refined Canola Oil: Smokes at approximately 204°C
- Corn Oil: Smokes at approximately 204-232°C
Other refined oils, like Cottonseed oil (420°F/216°C) and Grapeseed Oil (420°F/216°C) also fit on the edge of this category. In general, oils in this list are the ones that are the most flexible, which is why they're easily available almost everywhere. Photo by Steven Tom.
The level of refinement and the quality of an oil has a huge effect on its smoke point and final flavour, but you need to shop cautiously. As we've pointed out before, there's no nationally mandated standard for what qualifies an olive oil to be labelled as 'extra virgin'.
For High-Heat Grilling And Deep Frying
The highest-smoke point oils are generally reserved for high-heat frying, brushing on the grill, and deep frying. Some of these are best used because of their high smoke point and their flavour; others are so heavily refined that a high smoke point is pretty much all they have going for them. A few examples:
- Sesame Oil: Smokes at approximately 210°C
- Peanut Oil: Smokes at approximately 204-232°C
- Palm Oil: Smokes at approximately 232°C
- Ghee (Clarified Butter): Smokes at approximately 252°C
- Refined Soybean Oil: Smokes at approximately 257°C
- Avocado Oil: Smokes at approximately 271°C
Many people resist highly saturated oils for health reasons, but their high temperature tolerance makes them a solid choice for deep frying, stir frying, or other situations where direct contact with flame are required. Keep in mind that some of them -- notably peanut oil and avocado oil -- impart their own flavours to your dish, so only use them when the taste is complimentary. Photo by Jack Liddon.
Finally, a note about soybean oil -- soybean oil's smoke point varies quite widely based on its level of refinement. Unrefined soy oil can smoke as low as 160°C, while refined soy oil can go up 176°C. Almost pure soy bean oil is what's listed here, so remember that when you go shopping if soy oil is a staple in your home.
Keep Your Favourites On Hand
As we said earlier, there's no reason to keep a half-dozen oils in your pantry (besides, you don't want your oil to go rancid on you.) Pick a few that you really enjoy using, both for flavour and for temperature. This cooking oil comparison chart, made with the help of Lifehacker friend, nutritionist and registered dietitian Andy Belatti, does a great job of showing you which oils are best left for salads and low-heat preparations versus the ones that can stand a little heat.
I keep soybean oil, extra virgin olive oil, and sesame oil in my kitchen. The soy oil has the highest smoke point, so it's great for grilling or high-heat frying. The olive oil is tasty, and best for baking and low-and-slow sauteeing (and cold preparations, such as salad dressing) The sesame oil can stand high heat, so I use it for stir frying, but I don't shy away from using it to add flavour in colder preparations. I've been experimenting with coconut oil too.
Finally, keep your budget in mind. Some highly refined oils are pretty expensive, so do your homework before buying. There's nothing worse than buying an oil just because it has a high smoke point or someone's book says it's the cure for your ills only to find out it tastes terrible in everything. For a more complete guide to various oil types and their smoke points, check out this table at the Good Eats fan page (nicely formatted for copy/pasting), this chart from Cooking for Engineers, or Wikipedia's list of common oils and smoke points.