School of Wok Guide: Deep Frying

PREPARATION

Understanding Deep Frying

Unlike many Western recipes that call for a single frying temperature, Chinese cooking often uses multiple heat stages during the same cooking process.

For example:

• Thin foods such as battered prawns, vegetables or tofu are often fried at 180–200°C until crisp.
• Thicker cuts, such as chicken wings or bone-in thighs, benefit from:
  1. Starting on a high heat to quickly seal the exterior.
  2. Reducing to a medium heat so the meat gently cooks through to the bone without burning the outside.
• Some ingredients are oil-blanched, meaning they're briefly fried over a high heat just long enough to seal the surface before being finished later in a stir-fry or sauce.

Why Temperature Matters

The biggest mistake when deep frying is placing food into oil that isn't hot enough.

Oil Too Cold

When food enters cool oil:

• it absorbs oil before the surface seals
• the coating becomes greasy
• the food feels heavy instead of crisp

Bread is a perfect demonstration—it acts like a sponge, soaking up oil before eventually browning. Meat, fish, tofu and vegetables behave in exactly the same way.

Oil at the Correct Temperature

At approximately 180°C:

• the surface seals immediately
• moisture inside the food creates steam
• the steam helps prevent excess oil from entering
• the result is a crisp exterior with far less oil absorption

This principle applies to almost every deep-fried dish.

The High-to-Low Heat Technique

For thicker ingredients:

1. Heat the oil to 180°C.
2. Add the food so the exterior seals immediately.
3. Fry for 30–60 seconds until lightly golden.
4. Reduce the heat to medium.
5. Continue cooking gently until the centre is fully cooked.
6. Increase the heat again at the end if extra crispness is required.

This method creates food that's crispy on the outside while remaining juicy inside.

Checking Oil Temperature Without a Thermometer

A simple wooden chopstick or wooden spoon can be used:

• Few gentle bubbles = oil is warming but not ready.
• Steady fizzing = approximately frying temperature (around 180°C).
• Violent bubbling or smoking = oil is becoming too hot and should be reduced.

COOKING

School of Wok Tips

• Always start frying with sufficiently hot oil to prevent greasy food.
• Adjust the heat during cooking rather than keeping it constant.
• Thin ingredients cook best at a consistently high temperature.
• Thick cuts benefit from starting hot, then finishing over a gentler heat.
• Oil blanching is a valuable Chinese technique for ingredients that will be finished later in a wok.

FAQs

Why does my fried food turn greasy?
Usually because the oil wasn't hot enough when the food was added. The food absorbs oil before the exterior has a chance to seal.

Should I always fry at 180°C?
Not necessarily. While 180°C is an excellent starting point, many Chinese recipes deliberately reduce the heat during cooking so thicker ingredients cook through without burning.

What is oil blanching?
Oil blanching is a quick deep-fry at a high temperature that seals the outside of ingredients