Cantonese cooking tradition — the concept of wok hei was first articulated in Cantonese culinary writing; the technique is ancient but the scientific understanding is modern
Wok hei (wok breath): the complex aromatic character imparted to food by rapid, high-heat stir-frying in a seasoned wok over a powerful burner. Scientific components: Maillard reaction from the iron surface; volatile aromatic compounds from the oil reaching smoking point; pyrazine compounds from the wok's carbon seasoning; and the rapid charring of sugars in vegetables and proteins. Cannot be replicated on a home gas or electric stove — the BTU output of a restaurant wok burner (150,000+ BTU) is 10x a home range.
Smoky, slightly charred, complex aromatic — the distinctive flavour of Chinese stir-frying that is impossible to achieve without proper equipment
{"Temperature: the wok surface must reach 300°C+ for true wok hei — below 250°C and the food steams","Toss continuously: the food must be in contact with the wok surface, then exposed to oxygen, then back — alternating Maillard browning with steam-cooking","Small batches: overcrowding drops temperature; restaurant cooks never fill more than 1/3 of wok","The carbon seasoning contributes: old, well-seasoned woks produce stronger wok hei than new woks"}
{"Home approximation: high-carbon steel wok preheated 5 minutes, smallest burner on maximum, tiny batches — slightly better than impossible","The opening of the char kway teow cook in Malaysia or Cantonese wok master in Hong Kong — 200,000 BTU burners produce otherworldly results","Keeping all mise en place at room temperature helps; don't refrigerate proteins right before stir-frying"}
{"Home stoves — insufficient BTU output; the temperature simply cannot be reached","Overcrowding — food steams rather than fries; water released by ingredients drops the temperature","Pre-cooked or refrigerator-cold ingredients — lower the wok temperature significantly on addition"}
The Food of Sichuan — Fuchsia Dunlop