Think Twice Before Reusing Cooking Oil: Experts Warn of Hidden Health Risks

We all do it—save that leftover oil after frying pakodas or puris. But is it really safe? And how long does a fresh bottle of oil even last? We break down everything you need to know about cooking oil safety, from storage to reuse.

How to tell if oil has gone bad?

Unlike milk or bread, oil won't spoil in 3-4 days. But it doesn't last forever. When exposed to air, light, and heat, it undergoes oxidation and goes bad. Using old oil won't show immediate effects, but its free radicals can harm your body over time. **How long is each oil safe?** Each oil has a different shelf life. Refined vegetable or canola oil lasts 1-2 years if unopened, but you should use it within 6-12 months after opening. Extra virgin olive oil is good for 24 months in its pack, but only 3-6 months once opened. Coconut oil lasts for about 2 years. Sesame oil should be used within 6 months of opening. Flaxseed oil lasts 6-8 months unopened; it's best to keep it in the fridge after opening. Avocado oil stays good for about 6 months after you open it. **Also

First, check the oil's smell. If it smells sour or has a strange odour, it has likely gone bad. Don't use it if the taste is bitter, sour, or soapy. Other warning signs include a change in colour, particles settling at the bottom of the container, or the oil becoming thicker than usual. **Do this when buying oil** When you buy oil, always check the 'Best Before' or 'Use By' date on the pack. Remembering the date you opened the bottle will help you use it up within the safe period.

How to store cooking oil so it doesn't spoil?

**Keep it away from sunlight:** You should not keep oil near windows where it gets direct sunlight or near the gas stove where it's exposed to heat. **Use the right containers:** Dark-coloured glass bottles or steel containers are much better than plastic bottles for preventing oxidation. **Seal the lid properly:** Always keep the bottle's lid tightly closed to prevent air from getting in.

The dangers of repeatedly heated oil

**Lower smoke point:** When you reheat oil that's been used for frying, it starts to smoke much faster. **Toxicity:** Reusing oil repeatedly creates toxic substances like trans fat and acrolein, which increase the risk of heart disease and cancer. **How many times can you reuse fried oil?** You can reuse fried oil a maximum of one time, and only for tempering (after filtering it, within 1-2 days). You should never use it for deep-frying again.