Choosing the right cooking oil

• Types of oils
• Storing oils
• Are there oils I should avoid?
• Frequently asked questions
• Cooking with oils chart
• Download a PDF of our cooking oils brochure

Different oils fill different needs — for health, taste and cooking. For good health, our bodies need a variety of healthy fats that are found naturally in different oils. When cooking, it’s essential to know which oils are best for baking, sautéing and frying — and which are healthiest used raw. This guide will help you choose the right oils for delicious meals and proper health.

Types of oils

Natural fats contain varying ratios of three types of fats: saturated, monounsaturated and polyunsaturated.

Saturated fats are hard at room temperature. They’re stable, resist oxidation, and are found primarily in meat and dairy, but also in palm and coconut oil.

Polyunsaturated fats are liquid at room temperature and the least stable. They oxidize easily and are found in seafood and corn, safflower, soybean, and sunflower oils.

Monounsaturated fats are more stable generally than polyunsaturates. They’re found in canola, nut and olive oils.

The American Heart Association (AHA) recommends limiting saturated fats in the diet due to their association with cardiovascular disease. The AHA also recommends relying more on monounsaturates than polyunsaturated fats.

PRESSED VS. CHEMICALLY EXTRACTED

The oils at PCC may be less familiar than brands in mass-market grocery stores — for good reason. PCC buyers seek out natural oils that are mechanically pressed from the seed — by expeller, centrifuge or vacuum-press methods.

Olive, avocado and walnut oils, for example, are from soft fruit or nuts and need only expeller pressing and centrifuging; they may be labeled “cold pressed.” Hard oilseeds such as soy or canola usually require some pre-treatment such as steam before pressing, but natural extraction methods do not rely on chemical solvents.

In contrast, common mass-market oils generally are extracted with toxic chemical solvents such as hexane. These oils then undergo harsh treatment to remove the toxic solvent. More chemicals, very high heat and straining are used to deodorize and bleach the oils, rendering them inferior in taste, fragrance, appearance and especially nutritional quality.

UNREFINED OILS

Unrefined oils are filtered only lightly to remove large particles. Some such as sesame or olive oil may appear cloudy or have visible sediment after sitting. This does not compromise quality.

Unrefined oils are “whole” oils and their flavor, color and fragrance are more pronounced than in refined oils. Like unrefined whole grain flours, unrefined oils are more nutritious and have a shorter storage life than refined.

Unrefined oils are best used unheated in dressings, or in very light sautéing or baking. The natural resins and other beneficial particles in them burn easily and develop unpleasant flavors and unhealthful properties if overheated. If you choose to bake with unrefined oils, expect the flavor to be more pronounced.

REFINED OILS

Naturally refined oils are more thoroughly filtered and strained than unrefined, usually with some additional heat, but without harsh or damaging chemicals. Refining reduces the nutrient level and flavor. It also removes particles and resins and makes naturally refined oils more stable for longer storage, more resistant to smoking, and a better choice for high-heat cooking and frying. Fully refined peanut oil, for example, is a traditional choice for very high heat cooking and even deep-frying.

Other refined oils recommended for high heat cooking and deep-frying are “high oleic” forms of safflower and sunflower oil. These are from plants bred to be high in monounsaturated fats instead of polyunsaturates, which oxidize easily and aren’t suited for high heat. To check if it’s “high oleic,” read the nutrition panel on the bottle. It lists polyunsaturated and monounsaturated fats separately.

Storing oils

All oils, especially unrefined oils, should be refrigerated after opening to prevent oxidation and rancidity. Natural oils should smell and taste fresh and pleasant. Can’t tell? If in doubt, throw it out. Rancid fat isn’t just unpleasant in odor and taste, it’s also unhealthly. Studies indicate that rancid fats may promote cancer and heart disease.

We suggest keeping a small dispenser of your everyday oil in the pantry for what you’ll use in a week or so and keep the larger bottle refrigerated. Oil that’s firmed up in the refrigerator will liquefy at room temperature in a few minutes. Place the bottle in a container of warm — not hot — water for five minutes. The quality will not be harmed.

Are there oils I should avoid?

Avoid products with hydrogenated or trans-fats. Hydrogenated fats are highly refined oils that are hardened artificially in a chemical process so they cannot oxidize. They raise cholesterol and are the main source of dangerous trans-fats. Hydrogenated and trans-fats are found in many shortenings, margarines and processed snack foods that require a long shelf life.

The National Academy of Sciences has declared trans-fats unsafe in any amount. The Food and Drug Administration has ordered food manufacturers to disclose trans-fat levels on all nutrition labels by 2006.

Cooking with oils