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Remodelling measures during ongoing operations

Zwettler Beers

Open-heart surgery

For many small and medium-sized breweries it is a great challenge to carry out complex modifications during ongoing production without affecting the efficiency of the company. Brewers have often underestimated the upcoming actions, and the originally planning disintegrated in no time. Projects often ended in a cost explosion. The example of the Austrian private brewery Zwettl shows that this can be done differently.

  Ensemble of functional form and traditional brewery buildings (C) Felipe Kolm

The privately owned brewery Zwettl Karl Schwarz GmbH, Zwettl/Austria, was founded in 1708 and has been run by the fifth generation of the Karl Schwarz brewery family for 125 years. Since the brewery was taken over by Georg Schwarz in 1890, Zwettl has always oriented itself to the requirements of the times and, for example, electrified the brewery as early as 1897. Two decades later, in 1918 to be precise, the installation of the first refrigeration machine followed. After the hard years of reconstruction, fully automated bottling was introduced in the brewery in 1960. Since then, further energy-optimizing modernizations have been carried out, especially in the 80s and 90s of the last century. In order to be prepared for the future, a few years ago the management of the company decided to rebuild important installations. The planning for this began at about the same time as the celebrations of the 300th anniversary of the family brewery. True to its mission statement “Built on culture. Brewed for the future”, the Waldviertler Brewers laid the foundation for the operative implementation of this concept, the most complex one in the company’s history, with exact and detailed project planning in 2011.

New candle filters at Zwettl private brewery


For the time being, the basis for the modernization of the old equipment was the replanning and construction of the appropriate infrastructure. Among other things, it had become necessary to adapt the steam boiler plant, which consisted of two high-speed steam generators with a capacity of 1800 kg/h each. These no longer corresponded to the contemporary and sustainable steam generation in modern production plants and therefore had to be replaced by an efficient boiler plant. At the same time, the brewery’s electrical power supply was updated and a new transformer station was installed. In addition to the infrastructure, numerous investments in production machinery, such as the KEG plant, which was to be enlarged and required additional building capacity, were also pending. Urgent improvements were also needed in the filter systems and in the pressure tank cellar – not least due to the damage caused by the flood of the century in 2002. In Zwettl, it was also decided to replace the existing kieselguhr candle filter plus sheet filter with a new candle filter with kieselguhr precoating, which was constructed by M&L consulting. An essential part of the new concept was also the integration of a “juice kitchen” for the production of lemonades and new beer mixed drinks. The necessary dosing unit and the new flash pasteurization plant were provided by corosys. Taking into account these necessary and promising investments, the total project has been estimated at EUR 8.5 million in the meantime. The last project extension with a new laboratory as well as social and meeting rooms then produced a total volume of 9.3 million EUR.

Brewery plant at Zwettl private brewery

The special technical and also technological challenge was undoubtedly the modification during ongoing operation. The entire project required thorough and meticulous planning. For the brewery management it was clear from the very beginning of the planning that they would seek support from Joachim Ledwig, Ingenieurbüro Ledwig, Donaueschingen, and from the planning office Ecoplan Bauplanungen GmbH, Vienna. In the course of the preparations, it quickly became clear that sections already planned could not be realized without prior reconstruction work. The result of the planning work was therefore a six-stage master plan, which included not only the modification and new construction of the building structure but also the necessary reconnections and relocation of the brewery facilities. In detail the phases were as follows:
■ Phase I
March till May 2012: General measures for the construction of the new KEG plant; this included, among other things, the conversion and installation of
new water tanks. At the same time, the realization of the energy center began with the construction of the buildings for the steam boiler and transformer station.
■ Phase II
May till August 2012: Construction of the new KEG plant and the energy center.
■ Phase III
June till October 2012: Construction of the new filtration building with the subsequent installation of the new filter line by M&L Consulting and the dosing stations. Simultaneous installation of an appropriate CIP station for the pressure tank and filter area. The finishing of the work on the KEG plant and the technical building equipment, such as the compressed air generation, completed this phase.
■ Phase IV
September till November 2012: Construction of the hall for a new pressure tank area.
■ Phase V
October 2012 till June 2013: Expansion of the old pressure tank cellar area and start of construction in the new area. At the same time, the new flash pasteurization plant was installed and put into operation.
■ Phase VI
July till August 2013: Interior finishing of the production area and completion of the remaining works for the technical equipment of the production and storage halls.

Only a few interfaces

Thanks to the early and detailed planning of the overall project, it was possible to complete it quickly and production continued almost uninterrupted during the entire reconstruction phase. The private brewery Zwettl particularly emphasized the smooth cooperation of all suppliers involved. For example, during each phase of the project special attention was paid to creating a uniform structure at the end of the overall project. In order to guarantee the undisturbed production process without any loss of quality, provisional solutions had to be implemented as well. For example, the old filter was still in operation in project phases I to III, while the new line was put into operation in the newly built filter cellar. Only after this was the connection of the incoming and outgoing pipes to the new filter cellar carried out.
At the same time, corosys GmbH was working on the automation of the new pressure tank cellar. In addition to the measurement technology from ifm electronic GmbH, Essen, the scope of supply also included the implementation of the latest software based on ProLeit®. Initially, this only included the pressure tank and filter area. In the final expansion stage in 2012, all systems of the Zwettl brewery were represented in a process control software by ProLeit. The delivery of the automation hardware as well as the integration of the degassing system for the production of degassed water and the flash pasteurization plant were in the hands of the company from Hofheim am Taunus.

Tradition and modern timesThe modernization and reconstruction of the Zwettl private brewery is an example of successful project planning and realization. Specific planning and timely completion of the individual project phases in combination with the guarantee of the brewery’s production capability have become a successful “open heart surgery”. The private brewery Zwettl and its partners have succeeded in creating a structured, modernized and functional brewery without completely losing or risking the charm of the old. The old, grown structure of the brewery was only loosened up by modern architecture and adapted to the course of the brewing process. At the end of the project there is now an ensemble of functional form and traditional brewery buildings, paired with a competitive and modern production technology.


Armin Burkert
Project manager corosys Prozeßsysteme und Sensoren GmbH, Hofheim am Taunus

Stefan Meyering
Project manager corosys Prozeßsystemeund Sensoren GmbH, Hofheim am Taunus

Heinz Wasner
Brewmaster, Privatbrauerei Zwettl Karl Schwarz GmbH, Zwettl/Österreich

Brauwelt 36/2015


Kerstin Dittrich
Contact Publishing
Kerstin Dittrich

Phone: +49 6122 70 75 – 0

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