Korean soy sauce, (called Joseon ganjang=조선간장, in Korean) is a byproduct of the production of doenjang (Korean fermented soybean paste). Joseon ganjang, thin and dark brown in color, is made entirely of soy and brine, and has a saltiness that varies according to the producer. Traditionally in Korea, we have different kinds of soy sauce, depending on the length of the fermentation time. Basically we use 2 types of soy sauce the most. One is normal soy sauce, which is fermented for more than 3 years. The other is soup soy sauce which is fermented for 1 or 2 years. The longer you keep the soy sauce the darker color, and the stronger flavor. Nowadays, many Korean people just buy soy sauce from the store instead of making it at home since it is difficult and time consuming.
Keep in the cabinet.
I highly recommend the Korean brand of soy sauce called