A plate heat exchanger rig was developed at Dublin City University to study fouling of plate heat exchangers using cheese whey solutions. The rig consisted of an Alfa-Laval plate heat exchanger, 316 stainless steel pipework, pressure and temperature measurement and was temperature controlled with all information logged via an Anville data acquisition system. Cheese whey solutions of various concentration were passed through the plate heat exchanger for periods of up to four hours. The effect of flowrate, temperature, whey concentration and cleaning on fouling resistance were investigated. Increasing the processing temperature was found to increase the rate of fouling Maximum deposition on the plates of the heat exchanger was found to occur at low whey flowrates Increasing whey concentration was found to increase the rate of fouling. An induction period was noted and asymptotic fouling found to occur at low flowrates and high temperatures. Cleaning of the plates of the heat exchanger was found to significantly affect the rate of fouling.