Napa cabbage
"Baechu kimchi" is prepared by inserting blended stuffing materials, called "sok" (literally "inside"), between layers of salted leaves of uncut, whole Napa cabbage. The ingredients of "sok" () can vary, depending on the regions and weather conditions. Generally, "baechu kimchi" used to have a strong salty flavor until the late 1960s, before which a large amount of "myeolchijeot" or "saeujeot" had been used.