Réaction drôle devant quelque chose qu’on n’ose pas manger

What does “ça se mange” mean in French?

Ça se mange ? looks reflexive but isn’t. French uses se + verb to say what is generally done with a thing, without naming anyone who does it — so this asks “is that edible?” or “do people eat that?” The same move gives ça se dit (“people say that”), ça ne se fait pas (“that’s not done”), ça se voit (“it shows”) and ce plat se mange froid (“this dish is eaten cold”).

Grammar books call it the pronominal de sens passif — a pronominal verb doing the work of a passive, and much lighter than the full est mangé par construction. It is why comment ça se prononce ? is the natural way to ask how a word is said, and why recipes write ça se sert bien frais. In the past tense the participle agrees with the subject: ces livres se sont bien vendus.