Specialty dosing vessel and additional trub screen
The brewhouse was designed with a special focus on the specific requirements of craft brewers. Warner pointed out: “In the planning and design phase, the Ziemann team was very creative and open-minded to our requirements. In our project, for example, a specialty dosing vessel was installed for the first time, with which we cannot add only cone hops, but also dose automatically ingredients like coriander seeds or citrus peels.”
In simple terms, this system consists of a larger dosing vessel with an integrated hop strainer. The hops or the ingredient is placed in this hop strainer, and the vessel is flooded from the bottom to the top with hot wort. After a selectable leaching time, the flavored wort runs off and the hop cone or other solids are reliably maintained in the strainer.
The dosing can be carried out at different times. At Karbach, the dosage can be carried out during the wort boiling process, during the transfer from the wort kettle to the whirlpool or during the transfer from the whirlpool to the wort cooler. The entire process is fully automated. Only the respective ingredients must be added or removed manually.
A second individual craft brewer solution is the strainer station, installed between the whirlpool and the wort cooler. This station was developed for Karbach as once a year it brews an extremely hopped beer. For these brews, the additional strainers act as a security equipment, which reliably keep back the hot trub from the wort cooler. Thus, high yields can be achieved in this extreme separation process without running the risk that too much hot trub enters into the fermentation cellar. This strainer station operates fully automatically. A pressure transmitter is installed in this strainer unit. If the transmitter gives the signal for an exceeding of the specified limit value, the station switches to the second strainer and the first one is backwashed.
What about the practical experiences? Definitely good!
In addition, Warner pointed out the very short implementation period due to the very high degree of prefabrication in the Ziemann workshop in Germany: “We had a very tight time schedule. The kickoff meeting took place in November 2013. The contract was signed at Christmas 2013. The brewhouse was delivered in August 2014, and the first beer was brewed in November 2014.”
It was one year from the kickoff meeting to the first brew, and what were some of the practical experiences gained in between? Well, the Colibri mash mixer provides a thorough and homogeneous mixing of the dry grist with the water. This is the ideal preparation of the mash for the Lotus lauter tun, which at Karbach must cope with enormous challenges. “We brew beers with an original gravity between 11 and 22 °Plato and the associated malt charges, which also include significant amounts of wheat malt,” explained Warner. “For this purpose, we need a lauter tun, which is able to meet these requirements. With the Lotus, we have the ideal equipment.”
The Shark wort boiler once again proved itself through its gentle boiling with its controlled energy input and an excellent trub formation. These observations were verified analytically during the technical acceptance of the brewhouse, which the VLB Berlin carried out under the direction of Dr.-Ing. Roland Pahl. For the acceptance test, three Hopadillo brews were analyzed in terms of the performance characteristics and wort parameters according to DIN 8777:2010.
In 80 to 90 percent of the lautering time, the wort turbidity of the analyzed brews was below 40 EBC. This is far better than specified in the standard. The same applies to the solids content. This value was, on average, 50 mg/l and thus significantly less than the maximum value of 100 mg/l, specified in the DIN standard.
With a TBI increase of less than 15 during the actual boiling process and less than 10 during the whirlpool step, only about 50 percent of the allowed values were measured. According to VLB Berlin, these values document a very gentle boiling process. The DMS values between 40 and 50 ppb also meet very well the DIN specifications.
Higher yields, perfect flavor matching and the next expansion stage in sight
The proven whirlpool design with inverse conical bottom and 2° slope also provided an excellent service. During the technological acceptance test, the values for the solids content at the outlet amounted on average to 48 mg/l. For comparison, the recommended maximum value amounts to 70 mg/l. Warner also focused on a second parameter: “Our yields have improved dramatically. The brewhouse technology and the unique whirlpool design help us to get the last drop of wort out of the trub, even with Rodeo Clown, our Double IPA with an original gravity of 21.5° P and 85 bitter units.”
With the new brewhouse, the objective of more yield was achieved, but what about the taste and flavor matching of these successful beers? It must be taken into account that the exchange of the brewhouse and the cellar plant is similar to open-heart surgery. For Warner it wasn’t a big issue: “We managed it very quickly, without many optimizations. Now, the beers even have a rounder, more harmonic taste. In addition, the automated processes ensure a higher quality consistency.”
All in all, it was a long but rewarding step for Karbach Brewing into the 21st century of brewing. Finally, Warner announced that this isn’t the last step: “We are already tackling the next expansion phase and have ordered six additional tanks at Ziemann. At the end of 2015, our annual output was 65,000 hectoliters. Even in the land of opportunity, this is an extraordinary story. A few weeks ago, we celebrated only our fourth anniversary.”