What determines whether a food is acid or alkaline? It's not how the food tastes, rather it is the "residue" that is left behind after digestion which determines whether or not a food is acidic. For example some foods generally thought of acidic, such as tomatoes, are actually alkalizing to the tissues because after digestion the "residue" is alkaline.
For further reading: The Acid-Alkaline Diet for Optimum Health. by Christopher Vasey, N.D.