I was perusing a few of my favorite books last night (McGee, Patterson) and now I can't remember in which one I read that one should not used "dutch-process" cocoa powder with baking soda. Apparently it leads to a soapy taste. So... does anyone have any experience with this? Used dutch-process cocoa powder with baking soda/baking powder as a levener? Anyone have any idea how much acidity is needed in the cocoa powder for the baking soda to work properly with it?