Heating oil is one of the most important skills in cookery, however, don’t be fooled into thinking that achieving the right temperature is tricky. You really don’t need perfect judgement, cooking that way would make even the most experienced chefs nervous.
The most accurate method of checking your oil temperature is a thermometer. If you don’t have a thermometer, and I don’t use one, here are my favourite methods.
The chopstick / wooden spoon method
To test the temperature of oil for stir-frying dip a wooden chopstick or the tip of a wooden spoon into the oil. You can use any wooden utensil, the important thing is that whatever you use it has to be food safe and unvarnished.
When you dip the chopstick into the oil, it will start to fry, and you can tell how hot the oil is by the bubbles.
- If nothing happens or the bubbles are small and slow moving, it’s Cool. The oil is too cold for most cooking.
- If you see bubbles gently rising to the surface and popping the oil is Medium. Around 120ºC the right temperature for gentle cooking in small quantities.
- If you see lots of bubbles moving fast the oil is Medium Hot. Around 180ºC the right temperature for stir frying and the most often used temperature.
- If the chopstick bubbles furiously the oil is Hot. The oil is too hot, for most recipes.
The wok method
This method works with a steel or iron wok and when you are only heating a small amount of oil. It’s not suitable for pans with a nonstick coating or deep frying.
Heat your wok until the metal starts to change colour or smoke a little. Pour the oil into the pan and gently swirl it around to coat the bottom ⅓ of the pan. It’s ready to start stir frying straight away.
Deep frying
Using a thermometer really is best for this, testing the oil with a little batter does work but it’s by no means fail safe. All my recipes will tell you the cooking temperature for your oil.
The smoke method
Many recipes say to heat your oil until it’s smoking, this is woefully inaccurate and requires you to know the smoke point of different oils. Unless you are already comfortable with smoking oil I don’t recommend it. Smoke means your oil is burning so you have to rely on the food you add to bring the temperature down.