A viscometer technique based on the measurement of the torque required to turn a propeller inserted into milk powders and a penetration test based on the measurement of force required to penetrate milk powder compacts were used to characterize stickiness and cake formation in whole and skim milk powders. These simple techniques were suitable for determining the sticky point temperature (SPT) of the milk powders. Furthermore, the techniques provided useful information regarding the sticking behavior of the milk powders prior to the SPT. The stickiness and cake formation in the whole and skim milk powders were quite different due to the significant variation in the surface composition of these powders. Effects Of Moisture content, applied load, temperature, and time on the stickiness of the milk powders were also established. (C) 2002 Elsevier Science Ltd. All rights reserved.