"Wok hei" () literally, the "breath of the wok", is a poetic phrase Grace Young first described to a Western audience in her cookbook, "The Wisdom of the Chinese Kitchen". In her book, "The Breath of a Wok", Young further explores the ideas and concepts of "wok hei". An essay called "Wok Hay: The Breath of a Wok" explains how the definition of "wok hei" varies from cook to cook and how difficult it is to translate the term. Some define it as the "taste of the wok", a "harmony of taste", etc.: "I think of wok hay as the breath of a wok—when a wok breathes energy into a stir-fry, giving foods a unique concentrated flavor and aroma."