Fin

In a casual conversation, my friend CB asked me about the nature of various types of shark fin. I am no professional gourmet, but it does no harm to share here what I know.

Let me put it in a Q&A format:

Q. What is "金山勾" ? (A poetic translation would be the San Francisco hook.)
A. First, it comes actually from Mexico rather than San Francisco - which is too cold for that particular species of shark and the place serves only as the export center. (The situation is similar to Boston lobsters, which are generally caught at the bay of Maine and transport to other places via the port of Boston.)

Q. What is "勾翅" ?
A. It is the pectoral fin of a shark. Traditionally, expert chefs of southern China consider it as the second best type; the very best is skirt fin (裙翅), which is the pelvic fin or anal fin.

Q. How about the dorsal fin and caudal fin ? Aren't they even bigger ?
A. They are so big that their basal parts are calcified, which need to be removed during processing. As a result, the fin fibers fall apart, and the thing becomes loose fin (散翅).

Q. Why Mexico then ?
A. Shark fins in that area are nearly white in colour and therefore most appealing. Those from many other parts of the world are dark yellow or brown when raw, which require bleaching (by smoking with sulfur dioxide). The whitish colour is nevertheless artificial, and, more importantly, the procedure leaves a tinge of sulfuric taste that could be detected by real gourmets.

Not me. Thank god.