Place the beans and lemon juice in a bowl.
Cover the beans with water, and let them soak for 12-24 hours.
Drain and rinse the beans.
Add the beans and three cups of water to a blender, and blend for about 2 minutes until it appears smooth.
Strain the mixture through a fine sieve or nut milk bag, removing the bean pulp.
Heat a pot over medium heat, and add the bean milk.
Stirring constantly, warm the bean milk for 10 minutes. BE CAREFUL to not let the mixture come to a rolling boil, only a low simmer. Otherwise, the milk will scald, and it will have a burnt taste.
Stir in the final cup of water, vanilla, salt, maple syrup, and stevia.
Pour into a storage container, and store in the fridge.
Use as you would regular milk!