The Right Cooking Oil

February 6, 2014  |  POSTED BY OpenDoor



Choosing the Right Cooking Oil

By Andrea Withey

 When you take a trip to your local health food store and find yourself in the cooking oil section, what enters your mind?  Are you looking for oil that will add flavor to your dish or one that is processed in a way that it retains its nutrients?  Each oil on the shelf varies in specific qualities and can fulfill different needs while they take you on your culinary adventures. There are some that are best used for high heat cooking, some that are used to add flavor to a dish and others with unique health benefits.  Let’s take a walk down that overwhelming isle and see if we can get a better sense of what the oils shine in these various qualities.

Before we dive into individual oils there are a few terms that should be understood.  How the oil is obtained is an important factor when choosing oil. 

 Expeller Pressing- This method involves pushing down on plant matter, typically oilseeds and nuts, with up to 15 tons per square inch of pressure.  This produces heat with temperatures of up to 300O F.  A disadvantage of this type of pressing is that it produces about 75% oil from the plant material.  Due to this low yield some companies will use chemicals to get the most out of the plant.  Coating the nut or oilseed typically with hexane, a petroleum-based chemical, before pressing will often yield more oil.  The chemical increases the yield by breaking down organic materials of the plant, often providing about 90% oil.1  This process results in an unfavorable effect on the flavor, color and nutrients of the oil.

Cold Pressing- This method involves applying far less pressure than expeller press methods.   There is still some heat produced based on friction of the press but it is considerably lower, ranging between 120O and 160O F.   This method is used mainly to maintain the flavor, color and aroma in addition to the vitamins, minerals and phosphatides of the plant.2   One thing to keep in mind with cold pressed oils is that unless it is a monounsaturated oil, such as olive oil, or has a high vitamin E content, such as camelina oil, it will be very vulnerable to heat, light and oxygen.

After the oil has been obtained by one of the above methods it may be refined or kept unrefined.

Refined- After the oil is pressed it is placed in a centrifuge to be filtered.  It is then treated with alkaline chemicals at a heat of 150OF, filtered again and steam deodorized at 460OF, bleached with charcoal or clay and finally filtered again at a low heat.  Synthetic antioxidants may be added back into the oil to extend the shelf life.  As a result to the refining process the oil will appear pale, odorless, tasteless and can withstand higher temperatures.3

 Unrefined- After oil is pressed it is lightly strained and filtered, requiring no added heat.  There are no added chemicals, bleach or deodorizers leaving the oil with its original color, flavor, aroma and nutrients.  Unrefined oils are generally more fragile, they should not be used for high heat cooking and used more quickly due to spoilage, unless it is naturally high in antioxidants.

When choosing an oil keep in mind what type of cooking you want to use it for.  Every oil has its own smoke point, the temperature at which you can visibly start to see smoke when heating oil.  Once oil has been heated at or past its smoke point the nutrients begin to degrade and toxins begin to develop.




Smoke Point o F

Avocado- Refined


Avocado- Unrefined




Canola- Refined


Canola- Expeller Pressed


Camelina- Unrefined


Coconut- Refined


Coconut- Unrefined


Corn- Refined


Flax Seed- Unrefined


Ghee (Clarified Butter)












Olive- Refined


Olive- Virgin


Olive- Extra Virgin




Peanut- Refined


Peanut- Unrefined


Rice Bran


Safflower- Refined


Safflower- Unrefined


Sesame- Refined


Sesame- Unrefined


Sunflower- Refined


Sunflower- Unrefined


Vegetable Shortening


Walnut- Refined


Walnut- Unrefined



Note that the refined oils have a higher smoke point than the unrefined.  They will also carry less of the plants natural aroma, flavor and color.  Let’s take a look at some oils that are not commonly used.

Avocado- Avocado oil is pressed from the meat of the plant to produce an emerald green, thick oil.  This green color is due to the high levels of chlorophyll and carotenoids of the plant.  It presents a rich, buttery, grassy flavor and aroma.  Due to its high smoke point it can be used in any high heat cooking. 6

 Camelina- Camelina oil is cold-pressed, unrefined and made from the seeds of the camelina plant.  It has a bold gold color with a grassy, nutty aroma and flavor.  It contains an abundant amount of omega 3 fatty acids, about 35%.  It is relatively low in omega 6 fatty acids, resulting in a favorable omega 3 to omega 6 ratio of 2:1. This oil is very unique because it is perfectly suited for an omega-3 supplement and it makes an excellent cooking oil.  The monounsaturated fat in the oil makes it suitable for high heat cooking.  It is high in vitamin E (100% RDA in 1 Tbsp.), which helps extend the shelf life to 18-24 months. 5

 Macadamia- Macadamia oil comes from pressing the meat of the nut, which produces a light nutty flavor and aroma.  It is delicate enough to use on salads or can be used at a medium to high heat to give a unique nutty flavor to your dish.  It contains up to 85% monounsaturated fats, has a 1:1 omega 3 to omega 6 fatty acid ratio and has an unrefrigerated shelf life of 1-2 years due to it’s high vitamin E content.  Oils that are high in monounsaturated fat are also high in omega 9, which help to lower LDL (bad) and raise HDL (good) cholesterol levels.

Rice Bran- Rice bran oil is extracted from the germ and inner husk of rice.  It offers a mild flavor and light brown color.  It has a very high smoke point making it a great oil for sautéing and frying.  It is made up of about 38% omega 6 and 2.2% omega 3 fatty acids.   Due to its natural antioxidant components if stored in a cool dark place you can expect your rice bran oil to have a shelf life of 2 years.

Enjoy incorporating a variety of cooking oils to your kitchen as a way of adding flavor, diversity and nutrition to your meals and life.



  1. What is Expeller Pressed Oil?  WiseGEEK website. Accessed January 12, 2014.
  2. How a Cooking Oil Press Works. Global Post website. Accessed January 12, 2014.
  3. Lair, C., Adler, J., Boutch, B. (2012). Fats, Oils & Salt. Bastyr University, Kenmore, WA.
  4. Smoke Point. Wikipedia website. Accessed January 18, 2014.
  5. Camelina Oil Benefits.  Ole World Oils website. Accessed January 18, 2014.
  6. Avocado Oil. Wikipedia website. Accessed January 18, 2014.



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