Soak the soybeans in water overnight or a minimum of 2 hours.
Drain the soybeans (some people remove the outer skin, I have done it countless times and can’t notice any important difference in texture if you choose to do it, plan for additional 20 minutes).
Blend the soybeans with 6 cups of water until well blended and any other additives you may have chosen (dates or vanilla).
Strain the mixture using a cheesecloth or nut milk bag or a fine-mesh strainer.
Pour the mixture into a saucepan and add 2 cups of water. Bring to a boil, and immediately bring it down to low heat.
Stir occasionally and skim foam (watch it close as it may go up, just as boiling cow’s milk would). This is why it is essential to cook on low heat for about 15-20 minutes.
Let it cool. If there is any need to skim it again, do so before storing it in a sealed container in the fridge for about 3-4 days.
You can adjust the water quantity depending on how thick you want your soy milk. Use yellow soybeans.
Boil on low heat; otherwise, you may notice some brown threads, which are nothing more than the remaining milk sticking to the bottom of your saucepan.
You can use other sweeteners like agave syrup or maple syrup. Just add these liquid sweeteners after boiling your Soy Milk (or they can even be added directly in the bottle and shake. Another option is to blend the cooked milk again with the liquid sweeteners or add any sweetener at all).
Add it little by little until the milk reaches your desired taste. The sea salt is optional; it simply helps to bring all the flavors together. Feel free to add other ingredients you might like, such as cinnamon or cocoa powder, at any point.