Chinese — Wok Technique — Heat Application Authority tier 1

Zha (炸) — Chinese Deep-Frying: Temperature Stages and Double-Fry

Chinese deep-frying (炸, zha) in a wok differs from Western deep-frying primarily in temperature management across multiple frying stages. Many Chinese fried preparations require two frying passes at different temperatures — a low first fry to cook through, a high second fry to crisp — called fu zha (复炸, double-fry). This achieves the paradox of a thin, shatteringly crisp crust over a fully-cooked, juicy interior. It is the technique behind Cantonese crispy pork, whole fried fish, spring rolls, and taro dumplings.

Chinese deep-frying at its best produces the same textural joy as the very best fish and chips or Southern fried chicken — the shattering crust over yielding interior — but applied across an enormous range of proteins, doughs, and vegetables.

Temperature stages: - 120-140C (gentle bubbling): First fry — cooking interior without browning exterior. - 160-170C (moderate): Single-stage frying for spring rolls, wontons, tofu. - 180-200C (high fry): Crisping stage, second pass for double-fried items. Only 60-90 seconds. The double-fry method: 1. First fry at 130C: 3-5 minutes. Interior is cooked. Exterior is pale gold, soft. 2. Rest on a rack for 5 minutes — steam redistributes. 3. Second fry at 190C: 60-90 seconds. Exterior becomes deep gold, crackling crisp. Wok advantage: The curved sides concentrate oil depth at the base — 1 litre of oil fills a 35cm wok to 6-8cm depth at center.

A wooden chopstick dipped into the oil is a rapid temperature test: vigorous bubbling = 170C+; moderate bubbling = 140-160C; slow bubbling = 120C. Allow double-fried items to rest on a rack (not paper towel) — the rack maintains air circulation under the crust, preventing steam-soaking.

Single-temperature frying: Attempting to cook and crisp in one pass — food is either undercooked inside or burnt outside. Overcrowding the oil: Each piece added drops the oil temperature significantly.

Eileen Yin-Fei Lo, Mastering the Art of Chinese Cooking (2009); Ken Hom, Complete Chinese Cookbook (2011)

Japanese karaage also uses double-fry technique at identical temperatures Belgian frites use two-stage frying — first at 140C, second at 190C — identical to Chinese fu zha