The Fundamentals of Oil
Oil is either plant, animal, or synthetic based fat used in frying, baking and some pharmaceutical applications. It is also used in condiments such as mayonnaise, tomato sauce, chutney and salad dressings to name a few and may be called edible oil.
Cooking oil is typically a liquid at room temperature, although some oils that contain saturated fat, such as coconut oil, palm oil and palm kernel oil are solid until heated.
Cooking with oil
When cooking with oil heat changes its properties. Oils that are healthy at room temperature can become unhealthy, so when choosing a cooking oil, it is important to match the right oil to the cooking required. Deep-fat frying temperatures are normally range between 170–190 °C
The following oils are suitable for high-temperature frying due to their high smoke point above 230 °C
- Avocado oil
- Peanut oil
- Sesame oil
- Sunflower oil
All oils degrade in time as a result of exposure to heat, light, and oxygen when not sealed properly.
In a cool, dry place and out of direct sunlight oils have greater stability, but may harden, although they will soon return to liquid form if they are left at room temperature. To minimize the degrading effects of heat and light, oils should be removed from cold storage just long enough for use.
By contrast, oils high in saturated fats, such as avocado oil, have relatively long shelf lives and can be safely stored at room temperature due to the low polyunsaturated fat content.
This is the temperature which an oil starts to burn and the smoke point is marked by “a continuous wisp of smoke.
Above the smoke point are flash and fire points. The flash point generally occurs at about 275–330 °C at which oil vapors will ignite but aren’t sufficient to stay lit. The fire point is the temperature at which hot oil produces sufficient vapors they will catch on fire and burn.