The invention provides methods and devices for heating or cooling viscousmaterials suchas meat emulsions useful for producing food and other products. The devicesinclude a heatexchanger comprising a first plate, a second plate attached to the firstplate, and a first spacer anda second spacer arranged between the first plate and the second plate. Thefirst plate, the secondplate, the first spacer, and the second spacer define at least one temperaturecontrolled passage fora product to pass through the heat exchanger.
