The paper outlines the yield efficiency of steam peeling. It was proven that peeling potatoes manually with sandpaper results in the lowest possible peel losses. These losses were desired or wanted losses. However, in practice steam peeling results not only in wanted losses but also in substantial unwanted losses of about 7.9%. A model was developed to predict peel losses and heat ring (HR) development during steam peeling. Based on this model it was shown that creating a homogeneous peel removal effect with minimum HR development should be the main approach to decrease unwanted losses during steam peeling in the future. (C) 2003 Elsevier Ltd. All rights reserved.