Water activity is an important parameter employed in definition of stability of foods. The water activity should lie within defined limits for a desired shelf life of food products. The value should be below the limit to prevent mould growth. In addition ,undesirable reactions such as non-enzymatic browning, fat oxidation vitamin degradation, enzymatic reactions, protein denaturation, starch geltinization and starch retrogradation are also slowed below the specified water activity .Measurements can be made conveniently below 5 minutes using the Water Activity Meter. The system available with us is from the renowned supplier Rotronics. It is a PC controlled system based on capacitance measuments run on HW4 software. Simultaneous loading of upto 4 samples is possible in a single run.