Is Canola Oil Refined? The Truth About How Your Cooking Oil Is Made

November 6, 2025 •

4 min read

Over 90% of canola oil crops in the U.S. and Canada are genetically engineered, and the vast majority of commercial canola oil is refined. Most people are unaware of the extensive process that transforms a tiny seed into the clear, neutral-tasting oil found on grocery store shelves.

Quick Summary

Commercial canola oil is highly refined, a process involving chemical solvents and high heat to maximize oil yield and ensure a neutral flavor. This refining process is distinct from less common unrefined versions like cold-pressed canola oil. A comparison of these production methods reveals key differences in flavor, nutrients, and potential uses.

Key Points

Most Commercial Canola Oil Is Refined: The standard canola oil found in supermarkets is refined to improve its stability, appearance, and flavor.
High Heat and Solvents Are Used: The refining process involves both high-heat treatment and chemical solvents, like hexane, to maximize oil extraction from the seeds.
Cold-Pressed Canola Oil Is an Unrefined Alternative: Some specialty products offer unrefined, cold-pressed canola oil, which is processed without high heat or chemical solvents.
Refining Affects Nutrients: The extensive refining process removes many of the oil's natural nutrients, vitamins, and antioxidants.
Refined Oil Has a Higher Smoke Point: The neutral flavor and high smoke point of refined canola oil make it suitable for high-temperature cooking, unlike its unrefined counterpart.
Organic Canola is Non-GMO and Often Cold-Pressed: Organic canola oil is required to be non-GMO and is more likely to be cold-pressed, which avoids the chemical solvent extraction method.
Understanding Labels is Key: Consumers must read labels to distinguish between standard, refined canola oil and less common, unrefined versions like cold-pressed varieties.

What Does it Mean for an Oil to be Refined?

The term "refined" refers to a multi-stage manufacturing process that removes impurities from an oil to make it more shelf-stable, neutral in flavor, and clear in appearance. This process is crucial for producing the mass-market canola oil that is so widely used for cooking and baking. Without refining, the crude oil would contain leftover seed particles, natural pigments, and flavor compounds that could affect its quality over time.

The Standard Refining Process for Canola Oil

The industrial production of most commercial canola oil follows a standard, multi-step process, often referred to as RBD, or Refined, Bleached, and Deodorized.

Extraction: After the canola seeds are cleaned and flaked, they are exposed to high heat to aid in oil release. A mechanical press, known as an expeller press, removes most of the oil. The remaining oil in the seed cake is then extracted using a chemical solvent, typically hexane, to maximize yield. The hexane is later recovered, leaving a crude oil and a meal that is often used for animal feed.
Degumming: This step removes phospholipids and other compounds that can cause cloudiness or instability in the oil. It is often done using water or a mild acid.
Neutralization: An alkali substance is added to the oil to neutralize and remove free fatty acids, which can contribute to rancidity.
Bleaching: In a misnamed but standard practice, the oil is filtered through a natural clay filter. This removes color pigments and other impurities, resulting in the clear, golden color of commercial canola oil.
Deodorization: High-temperature steam distillation is used to remove any unpleasant odors or volatile compounds that have formed during the previous steps. This results in a finished product with the neutral flavor and aroma that consumers expect.
Winterizing (Optional): This step involves cooling the oil slowly to crystallize and separate waxes and other solids, ensuring the oil remains clear at colder temperatures.

Refined vs. Unrefined Canola Oil

While the vast majority of canola oil is refined, there are unrefined versions, such as cold-pressed or expeller-pressed varieties. These are typically found in specialty stores and are produced with minimal heat and no chemical solvents. The table below highlights the key differences between these two types.


Feature	Refined Canola Oil	Unrefined (Cold-Pressed) Canola Oil
Extraction Method	High-heat mechanical pressing followed by chemical solvent extraction with hexane.	Mechanical-only pressing, with no or very low heat applied.
Flavor & Aroma	Neutral and flavorless, making it suitable for a wide variety of cooking applications.	Stronger, often nutty, flavor and aroma.
Appearance	Clear and light-colored due to the bleaching process.	Darker, brownish color from retaining pigments.
Smoke Point	Very high (over 400°F), ideal for high-heat cooking like frying.	Lower smoke point, making it less suitable for high-heat applications.
Nutrient Content	Refining removes many beneficial nutrients, antioxidants, and fat-soluble vitamins.	Retains more of the oil's naturally occurring nutrients, antioxidants, and vitamins.
Shelf-Life	Long shelf-life, typically around one year, due to the removal of impurities.	Shorter shelf-life due to the presence of natural compounds that can oxidize more quickly.

Health Implications and Consumer Choice

The refining process has led to a significant debate regarding the health impacts of canola oil. Critics of refined oils point to the loss of nutrients and the potential for harmful compounds to form during high-heat processing. For example, the high-heat deodorization stage can reduce the levels of antioxidants like vitamin E by up to 50%. Some studies have also indicated potential negative health effects, though research remains mixed.

Conversely, supporters highlight canola oil's low saturated fat content and favorable omega-6 to omega-3 ratio, which is generally better than many other vegetable oils. The high smoke point of refined canola oil also makes it a versatile and affordable option for a range of cooking methods. For consumers looking to avoid the refining process, organic cold-pressed canola oil is available, though it has a shorter shelf life and is not suitable for high-heat cooking. Ultimately, the choice between refined and unrefined oil depends on cooking application, personal health priorities, and budget.

Conclusion

The question, "is canola oil refined?" is best answered with a distinction between its common supermarket form and its less processed alternatives. The majority of canola oil available to consumers is indeed highly refined, involving chemical extraction and high-temperature processing to produce a clear, neutral oil with a long shelf life. This is a deliberate process designed for mass market appeal and functionality, particularly for high-heat cooking. However, for those concerned about nutrient retention or the use of solvents, cold-pressed, unrefined versions exist as a viable, albeit different, option. Understanding the processing behind your cooking oil allows for more informed dietary choices tailored to specific needs and preferences.

Here is a guide explaining the canola oil processing from a producer's perspective.

The Extraction and Refining Process of Canola Oil

Step-by-Step Production

Harvesting and Cleaning: Canola seeds are harvested and then cleaned to remove debris like stems and dirt.
Conditioning and Flaking: Seeds are pre-heated and pressed into thin flakes to prepare them for extraction.
Pre-pressing: Mechanical presses squeeze out the initial 60-75% of the oil from the flakes.
Solvent Extraction: The remaining oil is extracted using a solvent, most commonly hexane.
Solvent Removal: The hexane is stripped from the extracted oil using high heat and steam.
Refining: The crude oil undergoes degumming, neutralizing, bleaching, and deodorization.
Packaging: The final, refined oil is bottled and distributed.

Frequently Asked Questions

No, not all canola oil is refined. While the mass-market products found in most grocery stores are highly refined, unrefined versions like cold-pressed canola oil are available in specialty stores.

Refined canola oil has a very neutral, almost flavorless profile, while unrefined (cold-pressed) canola oil retains a stronger, nuttier, or more herbaceous flavor.

Commercial canola oil is refined to increase its shelf life, remove impurities, and produce a clear, neutral-tasting product that is suitable for a wide range of high-heat cooking applications.

Refining does strip some nutrients from the oil. However, major health bodies often consider it a source of healthy unsaturated fats. The health debate is ongoing, but for most consumers, it is not considered definitively unhealthy.

Unrefined canola oil will typically be labeled as "cold-pressed" or "expeller-pressed." If the label does not specify, it is safe to assume it has been refined.

Yes, the high-heat and chemical treatment involved in refining can significantly reduce the levels of naturally occurring nutrients, antioxidants, and fat-soluble vitamins.

The lower smoke point of unrefined oil is because it still contains impurities and compounds that burn at lower temperatures. The refining process removes these, giving refined oil a higher smoke point.