Cooking oils are a key part of cooking. They bring flavor and texture to your meals. But with so many choices, picking the right one can be tricky. Some oils work best for frying at high heat, while others are better for drizzling on a salad. The oil you choose not only changes the taste of your food but also its health benefits.
In this guide, you’ll learn everything about cooking oils — how they’re made, their uses, and how to store them. We’ll also cover which oils are the healthiest, which ones to avoid, and how to match the right oil to your cooking needs.
What are Cooking Oils?
Cooking oils are fats derived from plants and animals. These oils are used in a variety of cooking methods, including frying, baking, sautéing, roasting, and grilling. They can also be used raw, such as in salad dressings, or as a finishing touch to enhance the flavor of dishes.
Plant-based oils are typically extracted from seeds, nuts, fruits, or vegetables, while animal-based oils are made by rendering fat from animals ❶.
How are Cooking Oils Made?
Cooking oils are made through two main processing methods: cold-pressed and hot-pressed extraction.
Cold-pressed is done through mechanically pressing at low temperatures, typically without using heat. This method preserves the oil’s natural flavor, color, and nutrients. It is often preferred by health-conscious consumers since more beneficial compounds are retained ❷.
In contrast, hot-pressed uses heat treatment to extract more oil from the source material. This process often includes roasting the raw materials before pressing, followed by refining to remove impurities, which results in a more neutral flavor and higher yield.
While hot-pressing makes oils more stable and suitable for high-heat cooking, it also has downsides. The high temperatures can destroy some of the oil’s natural nutrients, antioxidants, and beneficial compounds.
Additionally, chemical solvents like hexane are often used in refining to maximize oil extraction ❸. These solvents may leave behind trace residues, which, if consumed in excess over time, have been linked to potential health risks, including digestive issues and nervous system effects.
What are Cooking Oils Made Of?
The primary components of cooking oils are triglycerides, which are made up of glycerol and three fatty acids.
These fatty acids can be classified into three main types: saturated fats, monounsaturated fats (MUFA), and polyunsaturated fats (PUFA).
Saturated fats, when consumed in excess, can raise LDL cholesterol levels, which may increase the risk of heart disease ❹.
Monounsaturated fats, on the other hand, are considered “heart-healthy” because they help reduce bad cholesterol ❺.
Polyunsaturated fats contain essential omega-3 and omega-6 fatty acids that the body needs for brain function and cell growth. However, maintaining a balance between omega-3 and omega-6 is important, as consuming too much omega-6 relative to omega-3 can lead to inflammation.
Some oils also contain natural antioxidants, such as vitamin E, which help prevent oxidation and rancidity.
Cooking Oil Smoke Points
The smoke point of cooking oil is the temperature where the oil starts to burn and release smoke. When this happens, the oil loses its flavor and nutrients, and can even produce harmful chemicals.
Oils with high smoke points are best for frying and cooking at high temperatures, while oils with low smoke points are better for dressings, drizzling, or cooking with low heat.
Algae oil has the highest smoke point of all cooking oils, with Algae Cooking Club's algae oil reaching an impressive 535°F. This makes it perfect for high-heat cooking like frying and roasting.
Types of Cooking Oils
Cooking oils are categorized into plant-based and animal-based oils, each with distinct properties and uses.
Plant-based oils are derived from seeds, nuts, fruits, or vegetables and are commonly used for frying, baking, and salad dressings.
Plant-based cooking oils include:
- Algae Oil: A heart-healthy oil high in monounsaturated fats. It has the lowest saturated fat content and the highest smoke point among all cooking oils.
- Olive Oil: Packed with antioxidants and healthy fats, olive oil is commonly used for sautéing, drizzling, and salad dressings.
- Avocado Oil: High in monounsaturated fats with a high smoke point, great for frying and roasting. Its mild flavor also works well in dressings and marinades.
- Coconut Oil: Contains medium-chain triglycerides (MCTs) that provide quick energy. However, it is high in saturated fat and best used in moderation.
- Canola Oil: A neutral-flavored oil with a high smoke point, canola oil is a popular choice for frying, baking, and general cooking. It’s affordable and widely available, but often highly processed.
- Soybean Oil: Widely used in commercial cooking, soybean oil is high in omega-6 fatty acids and is often found in processed foods. It has a neutral flavor and a high smoke point.
- Corn Oil: Refined for stability and featuring a high smoke point, corn oil is commonly used for deep frying, baking, and margarine production. However, it’s typically high in omega-6 fatty acids, which should be balanced in the diet.
- Sunflower Oil: A light-flavored oil with a high smoke point, sunflower oil is often used for frying and baking. However, it is usually high in omega-6 fatty acids, so it’s best consumed in moderation.
- Safflower Oil: Similar to sunflower oil, safflower oil is heat-stable and excellent for high-heat cooking like stir-frying, grilling, and baking. Its light flavor allows the dish's ingredients to shine.
- Peanut Oil: This nutty-flavored oil is highly stable at high temperatures. It’s commonly used in Asian and Southern cuisine.
- Sesame Oil: Comes in light and toasted varieties, commonly used in Asian and Middle Eastern cuisine.
- Flaxseed Oil: Rich in omega-3 fatty acids, flaxseed oil is delicate and unsuitable for high-heat cooking. It’s best used for salad dressings, smoothies, or drizzled over finished dishes.
- Hemp Seed Oil: Packed with omega-3 and omega-6 fatty acids, hemp seed oil is best used as a finishing oil or in dressings. Its nutty flavor enhances cold dishes and salads.
- Walnut Oil: A fragrant, nutty oil rich in antioxidants and omega-3 fatty acids. It’s best suited for cold dishes, salad dressings, or drizzling over finished meals to preserve its nutrients.
- Pumpkin Oil: Deeply flavorful and rich in antioxidants, pumpkin seed oil adds a unique touch to salads, soups, and desserts. It’s best used as a finishing oil due to its low smoke point.
Animal-based oils come from animal fats and are often used for deep frying, roasting, and enhancing flavor.
Animal-based cooking oils include:
- Butter: A versatile dairy fat that adds a rich, creamy flavor to dishes. It’s commonly used in baking, sautéing, and making sauces, though its low smoke point makes it less suitable for high-heat cooking.
- Ghee: A type of clarified butter with the milk solids removed, giving it a higher smoke point and longer shelf life. Ghee is a staple in Indian and Middle Eastern cuisines and adds a nutty, rich flavor to dishes.
- Lard: Rendered pork fat prized for its savory flavor and ability to create flaky textures in baked goods. It’s excellent for frying, roasting, and baking, especially in traditional and rustic recipes.
- Tallow: Fat rendered from beef or mutton, known for its stability at high temperatures. Tallow is ideal for frying, roasting, and searing, offering a rich, hearty flavor often used in traditional cooking.
- Duck Fat: A gourmet favorite known for its silky texture and rich, savory taste. Duck fat is commonly used for roasting, sautéing, and frying, particularly in French cuisine.
While plant-based oils are generally favored for their unsaturated fats and health benefits, animal-based oils provide a deep, savory flavor and are more heat-stable for certain cooking methods.
Healthiest Cooking Oils
The healthiest cooking oils are those that are low in saturated fat, high in monounsaturated fat (MUFA), and free from seed oils that may be highly processed. Here's a list of the healthiest cooking oils:
- Algae Oil: Exceptionally high in monounsaturated fat, it contains the lowest saturated fat and boasts the highest smoke point among all cooking oils. In fact, algae oil has 25% more omega-9 monounsaturated fat than olive and avocado oil.
- Extra Virgin Olive Oil: Packed with antioxidants and heart-healthy monounsaturated fats, this oil is perfect for drizzling over salads, dips, and dishes or for low-heat cooking to preserve its delicate flavor and nutrients.
- Avocado Oil: Rich in monounsaturated fats, it features a high smoke point. It’s a versatile option for frying, sautéing, and roasting without compromising its health benefits.
- Unrefined Coconut Oil: Contains medium-chain triglycerides (MCTs), which can provide quick energy, but should be used in moderation due to its high saturated fat content.
Unhealthiest Cooking Oils
The least healthy cooking oils are those high in trans fats, hydrogenated fats, or excessive omega-6 fatty acids. These oils can promote inflammation, raise the risk of heart disease, and contribute to other chronic health problems. They’re also often heavily processed and found in many packaged and fast foods.
Examples are:
- Partially Hydrogenated Oils: These contain artificial trans fats, which are banned in many countries due to their strong link to heart disease and other health risks.
- Soybean Oil: While commonly used in cooking, its high omega-6 fat content may contribute to inflammation if consumed in large amounts.
- Corn Oil: Heavily processed and rich in omega-6 fats, it can disrupt the balance of healthy fats in the diet.
- Cottonseed Oil: Often heavily refined and potentially contaminated with pesticide residues, this oil is also high in omega-6 fatty acids.
- Grapeseed Oil: Although marketed as healthy, it is extremely high in omega-6 fats and often extracted using chemical solvents, which can affect its purity.
How to Store Cooking Oils
Proper storage is essential to preserve the flavor, nutritional quality, and shelf life of your cooking oils. Here are some tips to help you maintain their freshness and prevent them from going rancid:
- Store in a cool, dry, dark place: Exposure to sunlight, heat, and moisture can cause oils to degrade quickly. Keep them in a pantry or cupboard, away from direct sunlight and humidity.
- Use an airtight container: Oxygen accelerates oxidation, which can lead to off flavors and spoilage. Always seal oils tightly after use to maintain their quality.
- Use a dark container: Light can break down oils over time. Opt for dark glass bottles or opaque containers to shield them from harmful light exposure.
- Avoid heat sources: Heat can cause oils to spoil faster. Store them away from stoves, ovens, or any other heat-producing appliances.
- Refrigerate if needed: Certain oils, such as flaxseed or walnut oil, last longer when refrigerated due to their delicate composition. Check the label for storage recommendations.
- Label and date: To ensure you're using oils at their freshest, label the bottle with the purchase or opening date and aim to use them within their recommended timeframe.
Remember, when in doubt, give your oil a sniff — if it smells rancid or off, it’s time to replace it.
Signs Cooking Oil Has Gone Bad
Cooking oil doesn’t last forever, and using oil that’s spoiled can affect the flavor of your dishes and even your health. Recognizing the signs of rancid oil will help you avoid these issues.
Here’s what to watch for:
- Smell: Fresh cooking oil should have a neutral or slightly nutty scent, depending on the type. If your oil smells sour, rancid, or off-putting, it’s a clear indication that it has spoiled due to oxidation.
- Appearance: Over time, oil can darken in color, become cloudy, or develop floating particles. These changes suggest that the oil has deteriorated and is no longer fresh.
- Taste: Rancid oil often tastes bitter, soapy, or stale, which can ruin the flavor of your food. If you notice an unpleasant or unusual taste, it’s best to discard the oil.
- Texture: Spoiled oil may develop a sticky or thick consistency, which is a sign of oxidation and breakdown. A change in texture is a strong indicator that the oil is no longer suitable for cooking.
Using rancid oil can compromise your meals and health, so it’s always better to err on the side of caution. If you notice any of these signs, replace the oil immediately.
Frequently Asked Questions
Can I substitute one cooking oil for another?
Yes, you can often substitute one cooking oil for another, but it depends on the recipe and the oil's properties. For example, if you’re out of olive oil for drizzling on salads, you can use algae oil instead. Similarly, for high-heat cooking like frying or roasting, algae oil can be an excellent substitute for avocado oil, as it has an even higher smoke point while maintaining nutritional benefits.
Is it safe to reuse cooking oil?
Reusing cooking oil can be safe if done properly, but it has its limitations. After frying, allow the oil to cool, strain out any food particles, and store it in an airtight container. Reusing oil multiple times, especially at high heat, can degrade its quality, produce harmful compounds, and give food an unpleasant flavor.
Can I mix different cooking oils when cooking?
Yes, you can mix cooking oils, but it’s important to consider their individual properties. Mixing oils with vastly different smoke points can be problematic if used at high temperatures, as the oil with the lower smoke point may burn.
Additionally, blending oils with strong flavors, like sesame or coconut, with neutral oils like algae oil might affect the taste of your dish.
The Bottom Line
Cooking oils are more than just an ingredient — they can make your meals tastier and healthier. Take the time to learn about your options, store your oils carefully, and make the most of your time in the kitchen!
Get started with Algae Cooking Club's chef-grade algae oil, a premium option that brings nutrition and versatility to your meals.
