1. Heating oil beyond its smoke point
Each oil has a limit. Once it starts smoking, it’s literally burning, releasing toxic fumes and breaking down into free radicals.
What to do instead:
Use mustard/groundnut for high heat, olive oil for low heat, and switch off the gas the moment oil starts smoking.
2. Reusing the same oil again and again
That big kadhai of “fried once, save for later” oil is a huge mistake. Reheated oil becomes thick, sticky and loaded with aldehydes that stress the liver and inflame the gut.
Rule:
Never reuse oil more than once. If it smells “old,” throw it.
3. Storing oil in sunlight or near the stove
Light + heat = oxidation. When oils oxidise, they turn rancid (even before you can smell it).
Fix:
Store oils in airtight, dark containers away from direct sunlight.
4. Mixing multiple oils in the same kadhai
People often keep topping up the same oil with whichever bottle is nearby. Different oils have different smoke points; mixing confuses the chemistry and speeds up breakdown.
5. Ignoring the type of cooking
Using olive oil to deep fry pakoras or refined sunflower oil for tadka are both wrong for heat stability.
Quick guide:
•High heat: mustard, groundnut
•Medium heat: sesame, coconut
•Low heat: extra virgin olive oil
Dining and Cooking