Mung bean, chickpeas and soybeans produce the most neutral tasting bean flours. But in general, they don’t taste very good before cooking, and used in large quantities, can even have a slightly bitter flavour that needs to be balanced out by something else.
Small amounts, though, (e.g. a few tablespoons) can be added to bread recipes for a protein boost, without affecting flavour or texture.
French bakers use flour that has bean flour (fava bean flour) added to it to enhance the dough. It shortens the time required for the first stage of fermentation, enhances the strength of the gluten, and gives the bread a whiter crumb as well.
Bean flours are used a good deal in cooking in southern India (as opposed to wheat flours in northern India)/
Bean flours can also be used to thicken soups; in soups, they generally need 3 minutes of cooking time.
Best stored refrigerated to extend their storage life, and slow down their going rancid.