Raw product from the balance tank is transported by a booster pump through the raw regenerator section where it is pre-heated by hot product in the pasteurized regenerator. The milk flows to an optional separator where cream is removed, and the butterfat content of the milk is standardized. The product then flows to the timing pump, which maintains a constant system flow rate. Raw product enters the heater section from the timing pump, is heated for pasteurization and flows through a holding tube to the Flow Diversion Valve (FDV). When pasteurization temperature is reached, the FDV directs flow of the pasteurized product to the pasteurized regenerator section. In the pasteurized regenerator section, pasteurized product is pre-cooled by raw product in the raw regenerator. A portion of the pasteurized milk can be by-passed around the pasteurized regenerator to yield higher outlet temperatures. Product enters the cooler section from the pasteurized regenerator where it is cooled to packaging or storage temperature. From the cooler section, the pasteurized product is either routed by a recycle valve to storage or recycled to the balance tank. A second valve is provided to permit flow to drain for start up and CIP functions.