The reason to soak the beans, according to what a professor of pharmacology once lectured to a friend of mine, is to START the process of germination.
Just like when you plant a seed and water it.
The bean is a seed. The process of soaking the beans is necessary to start the process of germination in order that the protein of the bean can be fully digested & assimilated by the human. He said that otherwise the protein is bound up in some form which is totally unassimilated by the human digestive system.
Now, I have NO idea if this is accurate; at the time she took that college course, it was presumably the best info available.
I have read in the meantime that it is also very important to soak the beans and RINSE & CHANGE THE WATER AT LEAST TWICE, because in the skin of the bean are a number of undigestible sugars which can cause havoc in the intestines, and who knows what kind of sugar-food they provide to cancerous tumors in the body?? These dangerous indigestible sugars are removed by soaking the beans.
I find it really interesting that when you were young, it was customary for your parents to serve buttermilk along with a bean dish, that's so interesting... how people "know" certain things about foods, even though Science hasn't yet figured them out.
I have read in the meantime that it is also very important to soak the beans and RINSE & CHANGE THE WATER AT LEAST TWICE, because in the skin of the bean are a number of undigestible sugars which can cause havoc in the intestines, and who knows what kind of sugar-food they provide to cancerous tumors in the body?? These dangerous indigestible sugars are removed by soaking the beans.<<<
That is how my sister cooks them and they are tasteless, even when I do the seasoning of them.