How many letters does the top answer for “the act of preparing something (as food) by the application of heat” have?

The most common answer is cookery (7 letters).

Crossword clue: the act of preparing something (as food) by the application of heat

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

cookery 7 letters wn-def

the act of preparing something (as food) by the application of heat

cooking 7 letters wn-def

the act of preparing something (as food) by the application of heat