The most remarkable preserved fish is katsuobushi, a cornerstone of Japanese cooking, which dates from around 1700 and is made most often from one fish, the skipjack tuna Katsuwonus pelamis. The fish’s musculature is cut away from the body in several pieces, which are gently boiled in salt water for about an hour, and their skin removed. Next, they undergo a routine of daily hot-smoking above a hardwood fire until they have fully hardened. This stage lasts 10 to 20 days. Then the pieces are inoculated with one or more of several different molds (species of Aspergillus, Eurotium, Penicillium), sealed in a box, and allowed to ferment on their surface for about two weeks. After a day or two of sun-drying, the mold is scraped off; this molding process is repeated three or four times. At the end, after a total of three to five months, the meat has turned light brown and dense; when struck, it’s said to sound like a resonant piece of wood.