Lookout for lagers

Texas might not seem the obvious place to look for Eastern European-style beer, but thanks to Czech and German immigrants, the town of Shiner has been home to a brewery for almost a century. Residents wanted a beer that tasted like home, so in 1909, they hired a Bavarian brewmaster named Kosmos Spoetzl. And at the beginning of the 21st Century, Shiner beer is still a favourite, with a worldwide following.

With this tradition of innovation, the 50-employee strong Spoetzl Brewery decided to expand its facility. 'Currently, we brew half a million barrels per year, which classifies us as a regional brewery,' says plant engineer Rick Baltson. 'We produce 11 200 cases per day from the 7.5 brews per day.'

The expansion of the brewery led to a need to improve the instrumentation and control of the process, Balston says. 'We test our beer in the lab for air, clarity, and haze. Previously, we brewed our beer through a process of hand calculation that left much room for error. Considering that we need to control the temperature of the brew process as closely as +/- 0.25degrees F, we needed a more efficient way both to track our historical process and ensure that we produce the best quality beer.'

The brewing process itself is multi-stage, with the grain undergoing several physical and chemical transformations. Spoetzl's beers, which include Shiner Bock, Blonde, Light and Winter Ales, use barley, which is malted - germinated and dried - in Minnesota, then brought into the brewery. After milling the grain, the brewers heat it in water to which gypsum salts have been added to produce wort, a sweet liquid rich in several different sugars, which eventually becomes beer.

This process, known as mashing, requires good control of temperature, as the mixture is heated to various temperature targets for specific amounts of time, to control the saccharification - the conversion of the starches in the malted grains into sugars. It's the amounts and proportions of the various types of sugars that define the qualities of the final beer, such as its dryness, body, and feel in the mouth.

Next, hops are added to the boiling wort to add flavour, and the mixture is cooled to the correct temperature for fermentation. The wort then moves into storage where it is fermented, again with tight control of temperature for the various recipes.After it has fermented, Balston's team filters out the yeast and separates off the beer, which is transported to the bottling plant automatically.

<b>Widespread monitoring</b>

'We chose National Instruments Lookout software for three areas of the brewery,' Balston says. 'The support areas such as utilities, ammonia, purified water, CO2, and water; filter areas; and the expanded tank farm.'

The Lookout-based control system runs on four Siemens Simatic 555 PLCs, interfaced via serial connections. The Lookout HMIs run on a Windows NT platform using Ethernet. 'The computers are located right on the factory floor for easy operator access,' says Balston, 'and a main server located in the engineering department provides an overview of all processes. We accounted for several different levels of access to maintain system security. Our total I/O count is approximately 3000 points, and we collect data from each point every one to five seconds.'

'In addition, we can track temperature changes throughout the year and view the plant on screen. We readily access all alarm information and analogue process variables - including temperature, pressures, control variables, and all discrete I/O points - through Lookout. Temperature control isn't the only use of the system, of course. Spoetzl also uses Lookout for recipe management, historical trending, and process control. 'By automating the process, we can maintain product integrity and real-time process overview,' says Balston. Lookout also interfaces with an Allen-Bradley PLC located in the main brewhouse.

Designing the system married high-tech techniques with the traditional methods of the brewery. 'A National Instruments Alliance Program member, Vista Technology, recreated our plant on screen exactly,' Balston explains. 'Because of the 3D rendition of the plant, we can view all the various processes occurring throughout the plant online. An operator in the tank farm, for instance, only has to flip an on-screen switch to turn the APV intelligent valves on or off. On screen, we colour-coded the system for easy viewing - switches are green when open and red when closed. In addition, an operator can check the levels in the tanks by interfacing with the Lookout screen.'

Lookout's HyperTrendfunction allows the brewers to perform historical trending, keeping track of the time and temperature variations of the tank farm throughout the year. This allowed them to improve management of filter operation by automating data collection and real-time analysis and integrating this feedback into alarms and actions. The old filter configuration required an operator's presence throughout the filtration process to monitor pressure gauges, determine clarity, and more.

<b>Keeping a lookout</b>

'Lookout successfully manages these functions with signals from our instrumentation,' Balston says. 'Therefore, we can leave the filter room and perform other vital brewing functions, knowing that Lookout is reliably dealing with alarm situations in our absence.'The new set-up proved simple to incorporate into the brewery's practices, Balston says. 'With minimal training, our operators adapted to the new system. They control our system more efficiently, so we can continue to produce our old-world beer one brew at a time.'