About 30 years. Carrion is a very classic food in Tibet. Strictly speaking, it is actually a kind of air-dried pork. The whole pig will be treated locally, then hung on the beam, then the surface of the whole pig will be sealed with smoke, and then left to dry for years or even decades. Although this kind of meat will give off a bad smell when hung on the beam, the worse it is, the more delicious it will be, and the longer it is left, the worse it will be.