The debate about which oil one should use every day – cold-pressed oils or refined oils rages on. Refined oils are commonly shamed for being processed, for being made in factories, for having chemicals used to make them clearer, smell better, etc. But where do both these categories of oils stand?
When you take oil-bearing seeds and crush them at room temperature, you get cold-pressed oils. But this cold-pressed oil is not 100% fat. The crushing of plant matter ends up adding some plant matter that is not fats, per see.
Some of this plant matter is rich in antioxidants and aroma molecules which are unique to the particular oil. However, these non-fat plant matter also burn very easily, which is a problem. We use fats in cooking because they don’t burn at regular cooking temperatures. This is why we use refined oils for cooking because they would have this contaminating plant matter completely removed from the oil. To separate this extraneous plant matter, the oil has to be heated, filtered, and mixed with chemical solvents to dissolve the impurities in the oil.
Moreover, in India, refined oils are required to be fortified with fat-soluble Vitamin A and Vitamin D, which is good for you as you can get these two critically important vitamins from your oil itself.
So, stop being afraid of refined oils!
Why use cold-pressed oils?
Cold-pressed oils have strong flavors but tend to burn easily at high temperatures. They would be good for using raw or for everyday sauteeing. Cold-pressed oils tend to be more aromatic and may include some of the beneficial antioxidant molecules from the plant source. However, it’s important to remember that anything that is not fat (a triglyceride) will burn at high temperatures. If you are going to pay a lot of extra money for cold-pressed oil, you’d be wasting it using it for high-temperature cooking methods like finishing tadka or deep frying (cold-pressed mustard oil is an exception). On top of that, if the oil is not properly filtered, some of the non-fat plant matter will burn into not-so-healthy by-products.
Why use refined vegetable oils?
Some sources of oils like sunflower simply cannot be cold-pressed because the oil will not be suitable for human consumption without refining. Refined oils go through an elaborate filtering and chemical treatment process that removes everything other than fats. Some of these solvents (like Hexane) are not good for health, but the right question to ask is – how much of it ends up in the actual oil? FSSAI has standards for what is the maximum allowed ppm (parts per million) amount of hexane and there have been studies showing that most well-known brands of refined oil do not have statistically significant amounts of hexane in them.
Refined oils that have a neutral flavor, do not burn at higher temperatures, and last much longer. Use refined oils when you want the flavor of the ingredients to come out and shine, not the flavor of the oil to shine. Also, use refined oils for deep frying.
So, which oil should you use for daily consumption?
BOTH!
Use the right oil for the right situation. Cold-pressed for low temperature, light sauteing uses where the aroma of the oil is important to the dish. Refined oils in high temperature situations (like finishing tadka and deep frying) and where the oil needs to be neutral tasting so that the flavour of other ingredients stands out.
