Shimmer & smoke

When you cook with oil that has been heated past its smoke point, you do more than impart a burnt flavour to food, writes Preety Tyagi

Different oils have different characteristics and specific purposes when it comes to cooking. Some oils are best for frying, whereas some are ideal for simply drizzling or using as garnish.

When it comes to cooking at high temperatures or deep-frying, it is important to choose oils that have a higher burning point. Having a higher burning point means that oil will start burning or fuming after reaching a higher temperature. When you cook with oil that’s been heated past its smoke point or burning point, you do more than impart a burnt flavour to the food.

Beneficial nutrients and phytochemicals found in many unrefined oils are destroyed when the oil is overheated. Overheating also creates harmful free radicals which can cause harmful heart health issues and severe diseases too. Some examples of healthy cooking oils are canola, mustard, corn, olive, peanut, safflower, soybean, and sunflower.

These oils can be used for cooking and deep frying but should not be reused again and again.

The oil turns into trans-fat if misused this way. Hence, oil should never be reused for cooking or deep frying.

For raw consumption or shallow cooking, olive oil, coconut oil and ghee are most ideal. There are many arguments about coconut oil and ghee being saturated fats and hence must be avoided. But our body requires saturated fats too. These should be a part of our diet but in limited quantities.

These fats have incredible amounts of micronutrition which provides for the better functioning of our digestive system and overall health.

It’s always better to go for extra virgin and raw oils and fats than refined. However, for purposes of deep-frying, refined oils can be used.

Smoke point refers to the temperature at which an oil starts to burn and smoke.

The smoke point of cooking oils varies widely. In general, the more refined an oil, the higher its smoke point, because refining removes impurities and free fatty acids that can cause the oil to smoke.

Refined oils typically have a neutral taste and odour and a clear appearance.

Light olive oil (light in colour, not in calories), for example, has been refined and has a higher smoke point (486 degrees Fahrenheit) than extra virgin olive oil (410 degrees F), which has not been refined.

Even so, the smoke point of extra virgin olive oil makes it suitable for many types of cooking.

Cooking on average home stoves, such as roasting in the oven and sautéing, pan-frying and stir-frying over medium-high heat, is typically done between 250 and 400 degrees Fahrenheit.

Other oils that have high smoke points (400 degrees F and higher) include avocado oil (refined), almond oil, corn oil, canola oil, grapeseed oil, peanut oil, safflower oil, sesame oil and sunflower oil. These oils are better suited for cooking at higher temperatures.

Unrefined oils such as flaxseed oil, wheat germ oil and walnut oil have a low smoke point and should not be heated.

Over time, heat and light can generate free radicals that degrade an oil’s taste and quality. Store cooking oils in a cool, dark cupboard or the refrigerator.

Some tips for oil usage, storage and consumption:

Any oil starts to degrade once it reaches its smoke point. So, if you accidentally let your oil smoke or catch fire, get rid of it and start over.

If oil smells bad, don’t use it. When oil is stored for too long it can become oxidised or rancid. It will have a distinct smell, and you should get rid of it.

Don’t reuse or reheat any cooking oil.

Buy cooking oils in smaller quantities to avoid wastage, and store them in a dark, cool place to keep them fresh longer.

(The author is a nutritionist.)