Rinse the dried soybeans thoroughly in cold water to remove dirt or debris. Also, pick out any dark or discolored beans.
Soak the soybeans in water for at least 8 hours or overnight (8-12 hours for best results). This step will help soften the beans and reduce cooking time.
Drain and rinse, removing any dark or discolored beans you didn't see in the first step.
Add the soaked soybeans to a medium/large cooking pot or Dutch oven, add 4 cups of water*, and the bay leaves and a pinch of salt if using.
Bring the preparation to a boil, then reduce to medium heat and simmer the soybeans (without a lid) for at least 2 ½ to 3 hours, or until they are soft and tender, skimming off the foam that will rise to the water's surface and the hulls. Check on the cooking soybeans now and then, stirring occasionally **.
Once the soybeans are cooked and soft, remove the bay leaves if using, drain any excess water, and season with salt to taste (if desired).
Serve the soybeans hot as a side dish, or use them in your favorite recipe.