During the heat treatment of canned liquid foods in a spin-cooker, the cylindrical can is horizontally positioned and made to rotate around its longitudinal axis. Though a headspace of about 15% in volume is used, the air bubble is continuously displaced to the top affecting the internal level of turbulence in the liquid phase. For relatively high rotations all liquid is adhered to the cylinder rim (Rimming Flow regime), and the level of turbulence and the heat transfer are diminished. This experimental observation stimulates the identification of the flow regime. A dimensionless model to compute the transition speed to rimming flow in horizontal, partially filled cylinders is extended to take into account the effect of the cylinder length and to cover a wide range of liquid loads. Experiments supported the optimization of the coefficients of the dimensionless model, whose mean deviations in the computation of the critical rimming speed are less than 5.0% (C) 2003 Elsevier Science Ltd. All rights reserved.