Wednesday, September 21, 2011
What are the best fats or oils to use for cooking?
1. Saturated fats are more STABLE than unsaturated fats. Quite literally, the chemical structure of saturated fats will not be easily damaged by things that will easily damage unsaturated fats, namely heat, light and air. Ever wonder why your high-quality olive oils are sold in a dark green glass or other opaque container? It’s to keep light from damaging the oil. Ever wonder why coconut oil doesn’t go “off” or smell rancid from sitting out on the counter without a lid on it but a vegetable oil like corn or soybean oil will? Air oxidizes those oils and makes them rancid. That is, damaged beyond the point that they are already just from the point of bottling. What separates the saturated fats from the unsaturated fats is the presence of a hydrogen bond at every instance of a carbon in the chemical structure of the fat. When there is a double bond in the chain of carbons, it creates a more unstable structure, which you can see when a fat is liquid at room temperature: the group of unstable fats together form a liquid versus the group of stable fats together which form a solid or semi-solid.
2. Seed oils are extremely high in monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) at varying ratios, all of which are prone to oxidation, PUFAs most significantly. You wouldn’t cook with fish oil, would you? Why would you want to cook with other oils that are very high in PUFAs? Even beyond PUFAs, MUFAs are pretty easy to damage as well (olive oil is very high in MUFAs). Re-read this post for more on why canola and other seed oils all made by expeller and chemical extraction methods are already rancid once they’re bottled as well as this post on how they’re made.
3. BEWARE: Many refined seed oils are marketed as having a high smoke point, therefore making them “ideal” choices for cooking. That’s not really the whole story. A higher smoke point is valid only if the fat or oil is fairly stable to begin with, and it may be useful in determining between two fats which is more ideal to use. That said, simply using the smoke point as a reason why you choose a cooking oil is an ineffective tool and will leave you with an already rancid oil on your hands (most likely, due to how it was initially processed – see links above and the video below on how canola oil is made below) and one that you’ll possibly damage further with the high heat of your skillet.
So, which fats ARE safe and recommended for cooking?
I’ve created a handy chart for you of common cooking fats & oils ranking them in order of best to worst for cooking (see below). Note that this is not a complete list of every possible fat or oil that exists. Nor is it my comprehensive list of Fats/Oils: Which to Eat & Which to Ditch that you can download here. I will likely update the Ranking of Common Cooking Fats chart as I come across more information or have more resources at my fingertips since some of my usual resources are currently out of reach. What you can do is use the chart as a tool and see where the fat or oil you find may fall within the chart based on it’s fatty acid composition as well as it’s smoke point using resources like the books “Know Your Fats” and “Fats That Heal, Fats That Kill” as well as websites like http://wikipedia.com/ or others listing fatty acid composition of cooking fats/oils as a resource.
It’s safe to assume, however, that most naturally occurring saturated fats are safe to cook with, while most unsaturated fats (called oils because they are liquid at ambient room temperature) are unsafe to cook with and are most ideal for cold uses if appropriate for consumption at all. Remember that man made trans-fats are never healthy to eat: Crisco, Earth Balance, Smart Balance, Benecol, Margarine, Country Crock, I Can’t Believe It’s Not Butter and the new one claiming to be a coconut product but it actually contains soybean oil… yeah, those are all a “never.”
Before you post a comment asking about this oil or that oil… USE THE RANKING SYSTEM BELOW to figure out where it would fall. Those with the highest percentage of saturated fatty acids (SFAs) and with the highest smoke point rank at the top while those with the highest percentage of PUFAs and lowest smoke point at the bottom. Then, make the call for yourself whether you want to 1- cook with it, 2- use it cold- or 3- avoid it entirely.