You want to save the oil you used for the next time you cook, with all guarantees. What should you do? Here’s the 6 rules you have to follow to reuse oil healthily:
Rule #1. Use olive oil, which is more resistant to high temperatures.
Rule # 2. Never mix with new oil or other oils (sunflower seeds …) it will burn, producing irritating and potentially toxic substances.
Rule #3. Avoid overheating or discard overheated oil. If the temperature is too high unhealthy substances are also generated.
Rule #4. Remove the moisture from the food you’re going to fry because water promotes the oil breakdown.
Rule #5. Filter the oil after each frying to remove food debris which can oxidize and decompose.
Rule #6. Observe the appearance of the oil. It will give you many clues in your state. If you think it has darkened, it is much dense than the first time, or much liquid, remove it.
And remember, it is not advisable to use the same oil more than 3 or 4 times.