Olive Oil vs. Vegetable Oil and When to Use Each in Your Cooking

Choosing when to use olive oil or vegetable oil when you're cooking is key to a successful and delicious dish. Each of these oils has a different flavor and cooking profile and greatly influences how your food will taste. Learn the difference between olive oil vs. vegetable oil, according to professional chefs, including which type of oil is best suited to various cooking methods. 

What Is Olive Oil?

Olive oil is the liquid fat found in olives, the edible fruits of Olea europea, the olive tree. During the extraction process, a machine presses whole olives and then separates the oil and pulp. The oil can then be refined, a process that removes impurities. 

Types of Olive Oil

Depending on the specific production method, the final oil will be categorized into the following types:

• Extra virgin olive oil: Extra-virgin olive oil (EVOO) has a free acidity of 0.8 percent or less. It's cold-pressed and unrefined, meaning the extraction process doesn't use heat or chemicals. EVOO is considered to be the highest grade of olive oil, and it's less processed than refined oil, says Lenny DiMaria, executive chef at Patricia's of Holmdel in New Jersey.
• Virgin olive oil: Like EVOO, virgin oil is extracted without heat or chemicals. However, its free acidity is 2 percent or less. Its quality is considered to be slightly lower than EVOO, but higher than refined olive oil.
• Refined olive oil: Refined oil is virgin olive oil that has been refined with heat, yielding a lower-quality oil. "It tends to have little to no flavor," says DiMaria. This variety is often called "olive oil" or "light olive oil."

Nutritional Profile

Olive oil is rich in monounsaturated fatty acids. These "good" fats have anti-inflammatory properties and promote healthy blood cholesterol levels when used in place of "bad" saturated fats. However, compared to refined olive oil, EVOO contains more antioxidant compounds called polyphenols. (Antioxidants protect healthy cells by reducing oxidative stress in the body.) This is because heat and refining destroy polyphenols, so EVOO—which is minimally processed—naturally contains more.

Cooking Uses

In recipes, different types of olive oil are best for different applications. EVOO and virgin oil are less stable, meaning they can easily burn at high heat. These types are best for raw preparations, like dressings or drizzling on bread. Refined oil is more sturdy, making it ideal for cooking methods like frying, sautéing, and baking.

What Is Vegetable Oil?

Vegetable oil is a liquid fat extracted from part of a plant, such as the seed, nut, or fruit. There are many types of vegetable oils, including soybean, canola, sunflower, and peanut.

Depending on the source, "vegetable oil is expeller pressed or chemically extracted," says Stephen Chavez, senior chef-instructor at the Institute of Culinary Education. "For expeller-pressed [oils], the corn or seeds are put into a centrifuge, which spins and then presses the oil out."

Chemical extraction uses a solvent (chemical) to separate the oil from the plant part. In some cases, vegetable oil may be produced using both methods.

Types of Vegetable Oil

Once pressed or extracted, vegetable oil can be refined or unrefined. The flavors of unrefined and refined oils are similar, says Chavez. Otherwise, here are the differences:

• Refined oil: Refined oil has been bleached to remove its unappealing color, degummed to remove sticky materials that change the smoke point, and/or deodorized to remove colors and flavors. This refining yields a higher smoke point. 
• Unrefined oil: This type of oil has not been bleached, degummed, or deodorized, says Chavez.

Nutritional Profile

Depending on the type, vegetable oils are high in monounsaturated and/or polyunsaturated fatty acids, including omega-3 and omega-6 fats. When used in place of saturated fat, these fatty acids can help lower "bad" LDL cholesterol and increase "good" HDL cholesterol. Unsaturated fats also have anti-inflammatory properties.

Cooking Uses

The smoke point of vegetable oils varies greatly, making each one well-suited for different applications. "Vegetable oil is often used for frying, baking, and sautéing," says DiMaria.

Olive Oil vs. Vegetable Oil

Here's how olive oil and vegetable oil compare:

Fatty Acid Composition

Both olive oil and vegetable oil are low in saturated fat and high in anti-inflammatory unsaturated fats. However, olive oil contains more monounsaturated fats, while the unsaturated fats in vegetable oil vary by type. "For example, canola oil and avocado oil are highest in monounsaturated fatty acids, while soybean and corn oil are higher in polyunsaturated fatty acids," says DiMaria.

Heat Stability

Olive oil and vegetable oil have different smoke points or the temperature at which the oil starts to break down. The process "creates noxious fumes and free radicals, and the fatty acids will take on unpleasant flavors," says Chavez. 

In general, olive oil has a lower smoke point than vegetable oil, though it depends on the grade of olive oil. For context, the smoke point for both corn oil and soybean oil is 450° Fahrenheit. Meanwhile, the smoke point of olive oil is 350° to 410° Fahrenheit for EVOO and 390° to 470° Fahrenheit for refined olive oil.

Flavor Profiles

Olive oil has a green, earthy flavor, which is most vibrant in EVOO. In EVOO, the flavor ranges from fruity to spicy, says DiMaria. In contrast, vegetable oils have no flavor, says Chavez. They're known as "neutral oils," meaning they won't add flavor or change the taste of food.

Choosing the Right Oil for Different Cooking Methods

When choosing between olive oil vs. vegetable oil, consider the cooking method and desired flavor profile for your dish. Here are the best oils for various types of cooking:

• High-heat cooking: Vegetable oil is best for high-heat methods like frying and sautéing. If you want to use olive oil, choose refined. Never reuse oil after frying, as doing so will lower the smoke point each time, says Chavez. 
• Medium-heat cooking: For roasting, both olive oil and vegetable oil will work, though olive oil adds more flavor. "For baking, most recipes use vegetable oil, so it doesn't [add] flavor," says Chavez. However, some baked goods, such as olive oil cakes, use olive oil specifically for the flavor.
• Low-heat cooking: Both oils can be used for low-heat methods and raw applications, such as dressings and dips, says Chavez. He generally instructs students to use extra-virgin olive oil for dressings and finishing dishes.