Ustersbacher is a classic small Bavarian brewery, with a portfolio built around a dozen beers, its own mineral water brand, and a selection of non-alcoholic beverages. The brewery is situated within a nature park and has been in operation and family-owned since 1605. Ustersbacher has always made sustainability a priority. Recently, the family has stepped up its investment in measures to conserve energy under an initiative they call “Der grüne Weg” (literally: “The Green Way”, or “Going Green”). Ustersbacher’s approach demonstrates that you don’t have to reinvent and implement everything all at once but that a steady focus on sustainability will also get you there.
The independent brewery began its push to “go green”, to make its beverage production environmentally friendly. The approach included employing consistent energy management in production operations.
Ustersbacher installed its first rooftop photovoltaic power station and has continued to expand it over the years. Today, the system has a capacity of one megawatt.
Ustersbacher built a pilot biogas plant fed with waste water, initially to reduce the water’s COD (chemical oxygen demand). The plant would later be used to generate power as well.
Krones conducted its first energy consumption inventory. At the time, Helmut Kammerloher of Krones’ Steinecker plant was already convinced: “We have to leave the carbon in the ground. We have to move away from fossil fuels, and a closed-loop system is the right way forward.” Ustersbacher’s management shared his view. And so, the two companies worked together to make his idea reality: a brewery with consistently low, product-friendly process temperatures in which thermal energy can easily be recycled. A central energy storage unit would significantly reduce the need for fossil fuels and also flatten peak loads. The result of their years-long collaboration was the Brewnomic concept, which Krones unveiled (as the Brewery of the Future) at the 2017 drinktec trade fair. The heart of the concept is an energy-independent brewery that generates its own power supply by recycling residual materials from the brewing process. In other words, it’s a brewery and a power station rolled into one.
As their first project, Krones and Ustersbacher upgraded the brewhouse, removing the decoction kettle and installing a new ShakesBeer mash tun for the switch to infusion mashing. At the same time, they also installed an EquiTherm energy recovery system, converting the existing vapor condenser for hot water production to a vapor condenser, which would now supply a lautered wort heater. The wort pre-chiller also produces hot (around 96-degree Celsius) process water. The EquiTherm system, which recirculates thermal energy, moves that hot water to the central energy storage tank. That thermal energy is then used to heat the mash tun.
At the time, Ustersbacher was already using hot water, but at high temperatures. “We were able to convert almost all systems to low-temperature operation, which is also gentler on the product,” explains Helmut Kammerloher. “The only processes still needing high-temperature water are the wort boiling and keg sterilization, both of which operate at around 130 degrees Celsius. All other consumers are connected to a central low-pressure hot water tank.”
In the same year, Ustersbacher decided to install a combined heat and power (CHP) system to take advantage of a government incentive program. On Krones’ advice, the CHP system was configured to have a single heat stream at a higher temperature, around 110 degrees Celsius. At the same time, the CHP system can handle a very high return temperature of around 84 degrees Celsius and thus directly processes the thermal discharges from most consumers in a low-temperature brewery. By contrast, a standard CHP plant typically delivers 80-degree Celsius water from the engine cooling process, whereas a return temperature of 70 degrees Celsius or lower is needed here. But a brewery seldom has thermal discharges in the 70 degrees Celsius range. Standard CHP systems frequently use the hot exhaust gas to help heat the kettle in a brewery, but the system is often subject to considerable load swings. Specialized circuitry and the high intake and discharge temperatures enable the CHP system in Ustersbach to provide a consistently high efficiency of over 90 percent.
Krones then installed a central low-pressure energy storage unit that is continually charged by the CHP system (and now also by the biogas plant) with temperatures at 110 degrees Celsius. In combination with this cascaded thermal energy storage system, the CHP plant is able to cover most of the thermal energy needs of the glass line, the CIP system, and other consumers.
The newly configured Steinecker brewhouse is inaugurated. “If you’ve got good equipment, you can brew good beer,” says brewery owner and manager Stephanie Schmid. “And we have proven that we can. In 2020, we won the German Agricultural Society (DLG) Award – the highest honor that a German company in the food industry can receive for their quality performance – and so we’re the best brewery in Bavaria.”
When the time came to update the filling process, Ustersbacher once again chose Krones, putting a new, 55,000 bph Modulfill HES filler into operation. The powerful hygiene concept includes a highly effective system for cleaning the exterior, a hygienic-design rotary manifold for product distribution, a capper/crowner that can be completely cleaned, and lubrication-free lift cylinders. CIP cap feed and fill level sensor adjustments are automated. The machine operator can monitor consumption of product water, compressed air and sterile air, CO2, and electrical power on the touch screen. In addition, the filler was designed to also accommodate higher filling temperatures, so that it could later be integrated into an energy recovery system.
Next, the team in Ustersbach and experts from Steinecker tackled the existing anaerobic digester. Krones suggested that the biogas it generated be used not only to power the CHP system but also for the hot water boiler. Until now, excess biogas was flared (burned off) because the system was not yet equipped to process the gas. Krones developed a new control system for the biogas based on the Botec F1 process control system to remove sulfur and excess moisture from the biogas. “We’ve been very satisfied with it,” says Josef Geh, the brewery’s technical director. “Now we can generate around one-quarter of our gas supply from waste water.”
Meanwhile, the brewery also uses spent yeast in the biogas plant, which has further significantly increased the plant’s output. “Of course, the reason this cycle from waste water to electricity and thermal energy works so well is because we operate continuously, in three shifts, from Sunday evening through Friday evening,” explains Stephanie Schmid.
In the same year, Krones also optimized the heat exchanger that is integrated into the bottle washer, adding flow deflection and guided convection in order to further reduce the return temperature of this thermal consumer. The modifications made it possible to reduce these temperatures from 104 to an average of 90 degrees Celsius at peak times. Control of the return temperature reduction is also handled by the Botec F1 system, which likewise improved thermal layering within the energy storage unit.
The last phase – for now – was Ustersbacher’s installation in summer 2020 of a CO2 recovery system from Krones. This, too, was an investment in sustainability as it uses existing resources – the carbon dioxide generated during fermentation. Without the recovery system, this CO2 would be vented into the atmosphere. At the same time, Ustersbacher Brauerei would have to purchase industrially produced carbon dioxide from a supplier. The system recovers 300 kilograms of CO2 per hour and saves up to 800 metric tons of CO2 per year. Ustersbacher uses the recaptured CO2 in the filling process for beer and soft drinks.
In addition, the cooling energy released when the CO2 is vaporized is fed into the central refrigeration unit, thus reducing the refrigeration plant’s consumption of electrical energy. The refrigeration system in turn uses CO2 for CO2 liquefaction since, in a closed-loop system, it is currently deemed the most environmentally friendly refrigerant.
The brewery’s next capital project will be to add energy recovery to the refrigeration system. Higher temperatures allow for lower refrigeration capacity, which in turn significantly improves the plant’s coefficient of performance (COP), that is its efficiency. Of course, that requires filling the beer at a higher temperature. Usually, finished beer in the bright tank is around 0 degrees Celsius. It is then bottled cold, at 6 to 7 degrees Celsius. The filled bottles may then need to be actively warmed to prevent ambient moisture from forming condensation on the cold bottles in their cases. If, however, the beer is warmed on its way from the filter to the unrefrigerated bright tank by way of a heat exchanger with specialized logic controls and flow metering – which in turn cools the jacket water from 14 to 6 or 7 degrees Celsius – you eliminate the need to warm the bottles and, at the same time, the cold jacket water becomes ice water that can then be used to reduce the load on the refrigeration system.
Breweries normally use ice water at 3 to 4 degrees Celsius to bring the temperature in the fermentation tank to 10 to 14 degrees Celsius for pitching. In Ustersbach, the ice water only has to be 6 to 8 degrees Celsius to achieve this pitching temperature for pale, bottom-fermented beers thanks to the warm water balance achieved with EquiTherm. This higher target temperature improves the refrigeration system’s COP and reduces its electrical power consumption.
“With the measures described above, Ustersbacher Brauerei has largely implemented Steinecker’s Brewnomic concept,” explains Helmut Kammerloher. “In my view, Ustersbacher is a paragon of sustainability. In part, that is because the family’s first priority is not to generate a fast return on investment but rather to make their production sustainable – and they’re willing to wait a little longer for the investment to pay for itself.”
For the decision-makers at Ustersbacher, the advantages are clear: “Thanks to the various measures we’ve taken to increase efficiency, we consume around 50 percent less energy in our operations than our industry peers,” says Josef Geh. “I encourage them to get on board!”
