Potato chip cooking process and apparatus includes controlled cooking of potato slices from the initial to the final cooking stages. Slices are deposited in hot cooking oil to develop a slice pack which is carried along a cooking path during which the pack is agitated and mixed by paddle means or tumbled so that the individual slices receive maximum contact with the cooking medium. The cooking path may be divided into one or more stages in each of which the cooking times and temperatures are selected and maintained to produce potato chips of different styles having a final moisture content in the range of 1.2% to 2%. Further disclosed are apparatus that includes temperature and oil circulation controls for the oil heat exchangers dedicated to each stage of a cooking protocol. A multiplicity of variable rate, rotatable paddle wheel assemblies are positioned along the cooking path for thorough agitation of the potato pack encouraging good oil contact with the individual slices and consistent, chip-to-chip final moisture content.