A Guide to Cooking Oils

Whether you’re dressing a salad, sautéing some vegetables, or deep-frying falafel, you’ve certainly been faced with the question: “which oil should I use?” With so many different varieties for an array of different applications, the choice can be tough, and when you mix in considerations for the health and environmental impact of your oil, the choice can be paralyzing. In this article, we’ll help clarify some details and lay out some rules of thumb to help guide you to the perfect oil for any occasion.

How Oils are Made

Most oils are produced by extracting or expelling various pieces of plant seeds or nuts. Extracting is a process that uses chemical solvents to pull the oil from seeds or nuts, while expelling is a mechanical process in which the oil is pressed out of the vegetable parts. The choice between those two processes can have a large impact on the health and performance of a given oil. 

Extracting often involves the use of hexane, a toxic gas that facilitates the process (though its toxicity is not transferred into the oil itself). This process typically degrades the nutritional content of the oil and can often create unsafe working conditions for manufacturers. High-heat pressing can produce oils that can handle more heat while cooking but will also degrade the nutritional quality of the oil itself. Cold-pressing (the process used to make extra-virgin olive oil) is typically preferred by those seeking the maximum flavor and nutritional value of their oil. TLDR: If you want flavor and nutritional benefits, cold-pressed, extra virgin oils are your best bet, but for high heat cooking, you may want to opt for more refined (heated) oils.

Cooking with Oil

You can break down most oil applications into the following three categories: flavoring & dressing, low-heat cooking, and high-heat cooking. Keeping in mind which application you’re moving forward with is a crucial step in choosing the right oil. Heating oil changes its characteristics, altering flavor, nutritional content, and viscosity, and heating an oil beyond its limits can result in burnt-tasting foods that can also be quite bad for you. The limit we’re talking about here is the smoke point, the temperature after which oil will begin to carbonize and smoke-up. There are times when this is okay/inevitable, like sautéing foods on very high-heat in a wok, but typically, you want to keep oil below this threshold.

So, what kind of oil should you use for each of the three applications? As a rule of thumb, flavorful, unrefined oils are your best bet for flavoring & dressing. These oils are the most delicious and typically retain the highest nutritional densities. For low/medium-heat cooking, unrefined oils, either neutral or flavorful, are typically the way to go. Cooking oils initiates the process of breaking down their flavor and nutritional value, so you generally don’t want to use a super-expensive, delicately flavorful oil in these cases. Additionally, assuming the heat is relatively low, a typical unrefined oil of decent quality won’t reach its smoke-point in this scenario. Finally, for high-heat cooking or deep-frying, you’ll want to use a neutral, refined oil. Flavorful oils will be scorched to bitterness in these applications, and refined oils will normally be your only option if you want to stay below the smoke point in these high-heat scenarios. 

Oil and Sustainability

Understanding the environmental and social sustainability of the (edible) oil industry can be tricky. Some plants are incredibly resource-intensive, and their environmental impact can be large across the board, but most oil-driven-agriculture can vary from producer to producer in both environmental impact and worker welfare. For example, the palm oil sub-industry is well known for its association with mass deforestation and poor working conditions, and while there are notable exceptions to the rule, this is an oil you can often assume isn’t the most sustainable choice. Meanwhile, the environmental impact of olive oil is lesser-discussed and can vary wildly depending on the producer. A rule of thumb in this category is to choose organic and fair-trade as often as possible. An organic-preference is not always synonymous with superior environmental impacts or working conditions, but it is very often the case with oil agriculture. 

Common Options

To help break down your choices with more detail, let’s look at a handful of common options.

Olive Oil

This is one of the oldest and most common cooking and flavoring/dressing oils on the market. If you’re looking for amazing flavor for your salads or sautéed vegetables, extra-virgin (cold-pressed) unrefined olive oil is your best bet. If you’re doing medium/low-heat cooking, virgin olive oil may be a better option due to its higher smoke-points, and for high-heat cooking (but not deep-frying), choose “light” olive oil. While olive trees are not the most resource-intensive crops, large-scale operations have placed immense strain on the environment, draining landscapes of their water and contributing to devastating soil erosion. So, if you’re shopping for a new bottle, choose organic and fair-trade when possible.

Palm Oil

You may not have heard of this one, but it’s almost certainly lurking in foods and products throughout your house. The incredible utility that this oil offers has resulted in an explosion of demand. Unfortunately, and unsurprisingly, this explosion has manifested itself in massive deforestation and a rapid decline in agricultural working conditions as corporations work to squeeze profit from this booming crop. In 2011, a sustainable certification for palm oil was introduced to allow responsible producers to distinguish themselves from the pack and to pressure the industry to move in a more positive direction. Unfortunately, this certification hasn’t been pursued at large, and many operations are deceptive in their pursuit of it. As a result, in the current state of the industry, it’s best to avoid this oil when possible. If you are using it, its highly refined state and neutral flavor make it an ideal candidate for deep-frying and other high-heat cooking. 

Canola Oil

Canola oil is an engineered oil product from the rapeseed plant, and gets its name from a shortening of “CANandian Oil, Low Acid”. It is common in the industry for it to be made from genetically-engineered plants and subject to aggressive extraction and refinement processes, degrading its nutritional value and posing a potential threat to the environment (due to agricultural issues often associated with large-scale GMOs). However, it’s a fantastic option for high-heat cooking, and can be sustainably/responsibly sourced, just be sure to buy organic and cold-pressed! 

Peanut Oil

Granted you don’t have a peanut allergy, this one of the most trusted oils for high-heat cooking and deep-frying. It has a high smoke point and light, nutty flavor, and compliments deep-fried foods and many Asian cuisines quite well. Be sure to use it relatively quickly, as it tends to go rancid within a few months of purchase. Peanut oil is not particularly impactful to the environment, though choosing organic when possible will likely reduce the impact of your purchase. 

Coconut Oil

Coconut oil has been embraced over the past few years as a nutritional gold mine, though the scientific community hasn’t reached a total consensus on that. It is, however, a particularly sustainable option when sourced from fair trade producers. As its demand has grown, many producers have resorted to clearing our coastal mangroves to make way for more trees, so supporting responsible producers is imperative. Beyond its health benefits and environmental potential, coconut oil is also incredibly versatile in the kitchen. It’s solid at room temperature, making it an ideal substitute for butter and other fats in vegetarian/vegan products, and it has a high smoke point, making it a great choice for medium/high-heat cooking. Just be sure to take into account the distinct coconut-flavor it imparts on your foods!

Grapeseed Oil

Grapeseed oil is a common favorite amongst cooks for its high smoke point and particularly neutral flavor and is often used for high-heat cooking and salad-dressings alike. As a by-product of winemaking, there is a large potential for sustainability with this oil, but as always, conditions can vary from producer to producer. Additionally, grapeseed oil is typically extracted, which means a variety of chemicals are used in its processing. Therefore, we recommend sourcing your grapeseed organically if possible!

Vegetable Oil

Vegetable oil is a mysterious blend of a variety of oils, often including soybean, corn, canola, peanut, olive, sunflower, safflower, and/or palm oils. As a result, determining the impact of your purchase can be a doozy. Additionally, this Frankenstein mixture is typically highly processed and refined, making it effectively nutritionally sterile. However, its high smoke point makes it ideal for high-heat cooking and deep-frying, and its neutral flavor all the more so. 

Avocado Oil

Like coconut oil, avocado oil is praised (rightfully so) for its high composition of healthy fats and other nutrients. Unfortunately, the rising demand for avocados internationally has placed a significant strain on the environment and has resulted in a lot of environmental degradation. So, you guessed it, buy organic and fair trade when possible. In terms of cooking, avocado oil is incredibly versatile. Unrefined varieties are fantastic for vinaigrettes and low-heat cooking, while refined varieties have unbelievably high smoke points and are ideal for high-heat cooking. 

Toasted Nut & Seed Oils

Including options like walnut oil and toasted sesame oil, these oils are often flavor bombs and are incredible ingredients to throw in dressings or drizzle over finished dishes. Most of these are quite delicate and will burn easily if cooked aggressively, so we recommend using them at room temp. or low-heat!