How do I deep fry safely at home?

Deep frying is straightforward if temperature and quantity are controlled, and genuinely dangerous if they are not. The two failure modes — oil overflowing and oil catching fire — both come from too much oil, too hot, unattended.

Safety

What you'll need

• Deep heavy pan
• Thermometer
• Neutral oil with a high smoke point
• Slotted spoon or spider (optional)
• Pan lid (optional)

Step by step

1. Use a deep heavy pan filled no more than a third.Food displaces oil and it bubbles up considerably. A third full is the rule that prevents overflow, which is what causes most oil fires.
2. Choose an oil with a high smoke point.Sunflower, rapeseed, groundnut or vegetable oil. Olive oil and butter burn at frying temperatures.
3. Use a thermometer and hold 175-190°C.Too cool and food absorbs oil and goes greasy. Too hot and the outside burns before the inside cooks.
4. Dry the food thoroughly before it goes in.Water in hot oil causes violent spitting. This is the most common cause of burns in home frying.
5. Lower food in gently, away from you, in small batches.Never drop it. Small batches keep the oil temperature up — crowding drops it and everything goes greasy.
6. Never leave the pan unattended.Not for a moment. Oil goes from hot to smoking to burning quickly, and an unattended pan is how kitchen fires start.
7. Drain on a rack rather than kitchen paper.A rack lets air circulate underneath so the base stays crisp. Paper traps steam and softens it.
8. Know what to do in a fire: turn off the heat and smother it.A metal lid or a fire blanket. Never water — it turns instantly to steam and throws burning oil across the room.

Tips

• Let oil cool completely, then strain it through a sieve and keep it in a sealed container. It can be reused several times.
• Discard oil that smells rancid, foams heavily, or has gone dark and thick. Reused oil degrades and eventually smokes at lower temperatures.
• Never pour oil down the sink. Let it cool, put it in a sealed container, and take it to a household waste site.

Common mistakes

• Filling the pan more than a third full — Food displaces oil and bubbling raises the level further. Overflow onto a hot ring is the main cause of oil fires.
• Putting wet food into hot oil — Water flashes to steam violently and throws hot oil out of the pan. Dry everything thoroughly first.
• Putting water on an oil fire — It vaporises instantly and ejects burning oil across the room. Turn off the heat and smother the pan.

Questions people ask