With wort cooling we change over from the hot to the cold phase of beer
production. After separation of hot trub the wort temperature is lowered to the
required pitching temperature. From the physical point of view, cooling is an
easy process. In practice, however, breweries can choose different methods of
heat transfer.
Economical cooling in one
stage
Single-stage wort cooling with pre-cooled brewing water
is considered as state-of-the-art. With this type of wort cooling the wort is
cooled to the pitching temperature in one pass. So all the heat used is
returned to the brewing process. Depending on the number of brews per day, the
brewing water is pre-cooled continuously or at certain times using low
electricity tariffs. Pre-cooling of brewing water is performed with cooling
brine, alcohol-water mixture or by direct evaporation of the refrigerant.
Besides brewing liquor cooling we can also offer two alternative systems: The
water storage system is recommended when operated with direct evaporation.
Direct evaporation is preferable for a high number of brews per day. In this
case continuous cooling without storage is necessary. Of course, this is done
fully automatically - and very effectively at high evaporation temperatures -
in a semi or fully welded plate and frame evaporator. However, to manage energy
and water surplus two-stage wort cooling was common practice. In the first
stage of the plate and frame heat exchanger, part of the thermal energy of the
wort was transferred to the brewing water. In this way preheated brewing water
was made available for the next brew. In the second stage, chilled water,
cooling brines, alcohol-water mixtures or direct evaporation of the refrigerant
were used to lower the temperature of the wort to pitching temperature.