Some people decide to soak the walnuts they buy from the store because it can really enhance the taste of them after they are washed thoroughly. It is important to soak the walnuts for at least 20 minutes until the water they are soaking in has turned brown. You might be surprised just how much of a difference this can make in the taste of the nuts after all of the dust and residue on the skin has been soaked off and floats to the surface.
Sometimes soaking nuts like these can also increase their nutritional value as well, though it is most commonly done in order to make them taste better overall. It is important to immediately discard water used in soaking walnuts and not to use it in a recipe of any kind.