With wort cooling we change over from the hot to the cold phase of wort 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 ways of heat transfer.
Economical cooling in one stage
In the past, 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; thus, 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. In terms of energy management, however, single-stage wort cooling with precooled brewing water is more useful. With this type of wort cooling the wort is cooled to the pitching temperature in one pass. So the total heat used is returned to the brewing process again. Depending on the number of brews per day, the brewing water is pre-cooled continuously or at certain times using less expensive electricity tariffs. Precooling 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 chilled water storage system is recommended when operated with direct evaporation, when cheap electricity tariffs are used and when the system works at a high evaporation temperature. 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.
Top marks for our wort aeration
After cooling the wort is aerated to increase yeast activity and to start the fermentation process. To ensure the necessary air or oxygen supply into the wort stream we have developed an aeration unit which is totally new in concept compared to other conventional aeration systems. Our unit treats the wort gently and works efficiently. The wort, which runs through the aeration nozzle, creates a slight vacuum which draws air into the unit. This action causes a very fine distribution of air bubbles over a very large contact area, which can then react with the wort. For the wort oxygen pick-up the large reaction area is very important. This is one of the many reasons why an independent examination and assessment carried out on several different aeration devices gave top marks to the Huppmann unit. The system is the foundation for obtaining the optimum yeast activity, and more precise fermentation curves. This guarantees superior quality beer.