I bought these Aduki beans at a good Health food store. I'm soaking them for about eight hours but they still seem too hard to me, they don't seem to have absorbed enough of the water, if at all. Should I keep soaking them? I am a little concerned about trying to cook them and they're not getting soft. I am also cooking them with vegetables witch I may not want to overcook. A few of them but very few have become soft, about 90% of them are still hard.