For wort cooling a plate heat exchanger is used. The cooling process is done in one or two stages. In a single-stage process cold brewing water is used as the single cooling medium. The brewing water can be cooled to approx. 1 °C in a separate chiller operated with glycol, ammonia or brine. The wort enters the plate heat exchanger at about 100 °C. Due to the interaction of the hot wort and the cold brewing water in the heat exchanger, the temperature of the wort is lowered to approx. 2 - 3 °C while the temperature of the brewing water is raised to about 80 °C. The brewing water is used for the next brew, so the energy is returned to the brewing process. In a two-stage process, the hot wort is first cooled by brewing water to approx. 20 °C and then secondly by glycol, ammonia or brine to the pitching temperature. The warm brewing water can also be used for the next brew.