Koing-jang

I made marinated soybeans several times using the cookbook Dok Suni. The recipe does not call to soak the beans before cooking. First time I tried the recipe, I followed the directions and the results were tasty but a bit tough. Now when I make them, I soak them overnight and the results are a bit more to my liking.

My question is: Is it traditional to use the black soybeans without soaking them overnight?