Brewing grows with the flow

Technical Director Ludwig Metz heads the brewing facilities at the Oettinger HQ. Originally from the German region of Franconia, Metz has been with the company for 28 years. It is where he learned his craft as master brewer and he even remembers working there with traditional copper brewing vats. Since 1991, he has watched the brewery gradually expand into a major company and pursued his own successful career path to become Technical Director. He knows the company like the back of his hand and it is not hard to imagine him in rubber boots and apron standing at a copper vat and inspecting the brew in the mash tun. “The only place we still brew like that today is at our traditional family location, the Forstquell Brewery in Fürnheim,” explained Metz. Everything at Oettingen and the other locations in Brunswick, Gotha and Mönchengladbach is highly automated.

At the new, state-of-the-art brewing plants, the only indication that beer is being brewed is the aroma of the simmering wort. Virtually nothing else remains to be seen of the process. Four huge stainless steel vats have been erected in the southern brewing plant that was constructed in 2002. “We start ten 1,000-hectoliter batches here every day,” explained Metz. The contents of the vats, whether malt mash or hops boiling in the wort, are now only visible through a small inspection port. Shiny stainless steel vats and pipelines are everywhere. This where the industrial production facility shows itself from its most modern side. Operating staff are few and far between. “We have two brewing assistants and a master brewer on duty in the brewery round the clock. That is all the staff we need here,” added Metz. And this operating crew oversees everything including plant technology systems such as the combined heat and power (CHP) module from mtu Onsite Energy and the absorption chilling plant.

A brew is born

Trucks deliver malt to the breweries where it is stored in silos until it is needed for processing. Unseen by any observer, the malt is ground in the malt-mill before being fed through pipelines to the mash tun and mixed with water to create the actual mash. As it is heated in consecutive stages, the mash releases its vital ingredients to determine the character of the beer to be produced – dark or light or with a stronger flavor. “It’s not just the quality of the malt that is critical here. Water quality is also crucial,” explained Metz. The mashing process takes around two hours. The brew then flows to the lauter tun where the solids from the malt are separated from the liquor. The remaining spent grain or ‘draff’ is drawn off through pipelines and at this point, visitors can catch a rare glimpse of the process as the draff is loaded onto trucks to be used in agricultural animal fodder or to produce bread or distillery products. The remaining wort flows through other stainless steel lines to the wort copper where it is mixed with hops and boiled for around an hour and a half. The brew is then cooled in the wort cooler before yeast is added and alcohol forms in the fermentation tank. When its work is done, the yeast is extracted and the beer is left to rest in a storage vat before the final stage in the process decides whether the beer is to be filtered to produce pilsener-type products or clear, light beer types. For naturally cloudy beers, the filtration process is bypassed and the product is directly bottled or filled into kegs in the filling plant.

Background processes keep things flowing

Brewing is an energy-intensive business. 300-400 liters of water are needed to produce just 100 liters of beer. Generating the necessary electricity, heat and cooling power also generates costs and negatively influences the environment. Oettinger investigated a range of possibilities to ensure its operations run at maximum efficiency and decided that the best solution was a combined heat and power (CHP) plant with an absorption chilling unit. “At our company we set great store by regional identity and brand awareness. That is why we commissioned a firm of consulting engineers from this area and why we opted for a top-brand CHP solution from mtu Onsite Energy in Augsburg using engines that are built in the region,” declared Metz. The ‘Moroschan’ engineering consultancy designed the facilities for the Oettingen location as well as for the brewery in Mönchengladbach and stipulated 5,000 hours of CHP plant operation a year. Downtime was to be scheduled outside brewing operations and 100% of the power generated was to be available for use by the relevant production facility. On this basis, the choice went in favor of an mtu 16V 4000 gas engine delivering 2,000 kW of electrical energy. Oettinger utilizes thermal energy discharged from the engine to heat the brewing water and in Oettingen, the exhaust is used to generate steam. “In Mönchengladbach we use the exhaust to heat water for the mash house,” explained Metz. In Oettingen, the engine’s thermal base load is sufficient to run an absorption chiller unit for cooling the storage tanks, for example. The absorption chiller unit alone accounts for 20% of requirements. Nevertheless, the natural gas CHP module is not the sole element in the company’s cogeneration concept. Beer production and the filling equipment needed to wash bottles and kegs use a lot of water and Oettinger cleans that water in its own two-stage treatment plant. In Oettingen, the biogas generated in the treatment plant is used to fuel the boiler house, for example, and is thus also utilized in the heating process.

Whether they are light lager-type beers, shandies and soda/beer mixes, wheat beers or naturally cloudy German-style Kellerbier, all of the brews produced are bottled or filled into kegs in the company’s own filling plants for distribution. “We deliver our products direct to trade outlets and that helps keep prices down,” said Metz. Oettinger also operates its own logistics service. Around 70 company-owned trucks leave Oettingen every day headed for the A6 autobahn. Of course, their route takes them past the traffic circle with the copper brewing kettle that once played its own role in the history of the company.