"For new jars, cover with seven jin of ash fire on top, wait until thoroughly heated, then coat with wax oil. …
"For new jars, cover with seven jin of ash fire on top, wait until thoroughly heated, then coat with wax oil. For old jars, they must be smoked at the beginning of winter. The method involves placing half a brick on the furnace foot, setting it on bricks matching the jar, and using a dry sorghum straw with controlled fire to smoke it as if steaming on a steamer, until black juice appears on the jar's edge. Then wash three to five times, and wait until dry before using. Lacquering would be even better."