Joseon ganjang, 조선간장 – Traditional Korean style soy sauce is a byproduct of the production of doenjang(soybean paste). Thin and dark brown in color, it is made entirely of soy and brine, is fermented typically for at least three years, and has a saltiness that varies according to the producer.
waeganjang, 왜간장/倭간장 – factory-made Japanese style soy sauce made from soybeans, wheat or barley, and salt.
Uses: Marinades, flavoring, dips, and stir fry.
Storage: Typically on a counter top or in pantry. Suggested shelf life depends on Manufacturer, but is generally from 6 months to one year
Substitute: Other soy sauce from Japan, China, Taiwan, or other Asian countries. Kikkoman is probably the most common substitute in the U. S. Recommend tasting before use as some may be more or less salty than Korean soy sauces.