Cooking Oil Smoke Points: What They Are and Why They Matter
Perusing the cooking oil aisle in any grocery store has gotten to be pretty overwhelming. There's safflower, sunflower, and sesame. Refined and unrefined. Prices ranging from a mere $2 all the way up to $25. And then there are labels mentioning something called a smoke point. This primer makes sense of it all so you know what oils to reach for when sautéing and deep-frying, and which options are best for low-heat cooking or simply drizzling on finished dishes.
What Is a Smoke Point?
Also known as a flash point, a smoke point is simply the temperature at which an oil begins to smoke and oxidize. Generally speaking, the lighter the color of the oil, the higher its smoking point. But more factors, like the age, quality, and level of refinement, also have an impact (more on that later).
Why Do Smoke Points Matter?
Once any oil begins to smoke, it starts to break down, altering its flavor and releasing free radicals. A substance called acrolein makes the oil taste burnt and bitter, which can quickly ruin a dish. But more importantly, once an oil exceeds its flash point, harmful compounds are released that have been linked to myriad health issues.
That's why reaching for the right oil is the most important step for healthy and delicious cooking. Reach for a pricey extra-virgin oil for high-temperature frying, and you'll likely end up with a scorched mess, not to mention waste money. But use safflower or avocado oils for frying, and you're setting yourself up for success.
Other Factors That Determine Smoke Points
Exposure to heat, light, and air quickly degrade the quality of oils, decreasing their smoke points. So as handy as it may be to keep your go-to bottle of general-purpose olive oil next to the stove in a pretty glass container with an open spout, it's the worst thing you can do. Ideally all oils should be kept away from the heat in a cool, dark, dry place like a cupboard - in opaque, closed containers that keep out sun and air.
The other thing to consider is how they've been processed. Refined oils like inexpensive vegetable and corn oils have been refined using industrial-level processes like filtering, heating, and bleaching to remove extraneous compounds and create a totally uniform product. Unrefined oils, on the other hand, maintain more of their color and flavor, and may contain some sediment. (Think of a cloudy extra-virgin olive oil, which is cold-pressed and immediately bottled - or a dark nut or seed oil that's minimally processed to preserve its flavor and color.)
These unrefined oils boast fantastic flavor and nutritional perks, but they're far more delicate and expensive than refined oils. Their smoking points are lower, and they go rancid more quickly, meaning they're best when used in small quantities in low- or no-heat applications where they're flavors can shine (like quick sautés, in vinaigrettes, or drizzled over veggies, fish, or meat) than in large quantities for high-heat cooking such as deep-frying.
Picking the Right Oil for the Right Use
- Avocado Oil: 520°F, good for searing, roasting, and sautéing, but also in vinaigrettes and as a finishing oil. Green color and mild, buttery flavor.
- Canola: About 400°F, works for deep-frying and other moderate-to-high heat cooking. Neutral flavor.
- Coconut: 350°F, ideal for baking and sautéing. Strong coconut flavor.
- Corn: 450°F, perfect for frying or other high-heat cooking. Neutral taste.
- Extra-Virgin Olive: 325°F, good for sautéing, vinaigrettes, and used as a finishing oil. Flavor can be grassy, fruity, or bitter, depending on the olive variety.
- Grapeseed: About 420°F, best used for stir-fries and sautés. Neutral flavor.
- Light/Refined Olive: 465°F, better for high-heat cooking than the extra-virgin variety. Neutral in taste. (Also sometimes labeled "pure" or "regular" olive oil.)
- Peanut: 450°F, a popular choice for deep-frying and cooking many Asian dishes. Nutty flavor ranging from mild to strong.
- Safflower: 450-510°F, great for any high-heat cooking method.
- Sesame (untoasted): 350-410°F, good for sautéing or other moderate- heat cooking.
- Sunflower: 450°F, ideal for deep-frying, grilling, and stir-frying.
- Toasted Sesame, Walnut, and Other Nuts: Smoke points vary by type of nut and level of refinement; best when left unheated and used in vinaigrettes or as a finishing oil.
- Vegetable: About 400°F, great for frying and sautéing. Neutral flavor.