"What kind of oil should I use for this and that.....?" is a question which I hear more from my friends than recipe itself.
So this is a quick guide on oils - what they are, where they came from, how they were made, and what's it good for?
Before getting into details, there is one thing which is worth mentioning. Every oil has "smoke point." It's the stage heated fat begins to emit smoke and acrid odors (= gives unpleasant flavor to foods.) In another words, "higher the smoke point, the better suited for frying." Many factors makes its smoking point difficult to determine, but here are the guideline: (I added butter just to compare...)
Butter: 175 C degrees
Corn, grape-seed, peanut, soy bean oils: 227 - 232 C degrees
Olive oil: 190 C degrees
Sesame seed oil: 190 C degrees
Sunflower oil: 198 C degrees
Canola (rapsolje) oil: 223 C degrees
Fat is one of the body's basic nutrients - our brain needs fat to function!
In general, oils come from vegetable sources - plants, nuts, seeds, etc., while butter come from cow milk.
Oils are extracted from its source by "solvent extraction method" (ingredient is soaked in a chemical solvent that is later removed by boiling) or "cold press method" (ingredient is heated to up to 70 C degrees before being pressed to extract oil.)
After extraction, it's either left in its crude state or refined.
Refined oils - most commonly found in super market. They have been treated until transparent, have increased smoke point and longer expiration time.
Unrefined (crude) oils - They are usually cloudy and have intense flavor and odor that clearly signals their origin.
I usually use grape-seed oil for frying (such as Wok) and never olive oil. However, olive oil is fabulous for drizzling over dishes.
Canola oil has distinctive aroma when heated, so I prefer using them for drizzling over salad, instead of using them for frying.