palatable?
Palatable usually implies more than just capable of being tasted; there is the sense that it is at least not unpleasant to the taste. In fact many things that would be considered unpalatable are so considered because they have too much to be tasted. I would suggest tastable but I don't think it's a very commonly used word. Likewise smellable. Merriam-Webster OnLine (http://www.m-w.com/) recognizes neither.