Malt Producer and Brewer Innovates Processes Using Brooks Mass Flow Controller with NEMA4X/IP66 Enclosure

Photo Courtesy of Rahr Eagle Brewery

Brewing beer is a highly controlled, multi-stage process where precise management of ingredients, temperature, and gas composition directly impacts fermentation performance and final product quality.

During fermentation, oxygen plays a critical role in yeast metabolism, influencing yeast health, fermentation efficiency, and flavor development. As breweries continue to scale production while maintaining consistent recipes, accurate process control technologies - such as mass flow measurement and control - have become increasingly important for managing critical variables like oxygen delivery. 

One company continually innovating in the malt and distilling industries is Rahr Malting Co., headquartered in Shakopee, Minnesota. A long-standing family-owned business, Rahr operates one of the largest single-site malting facilities in the world. 

Recognizing that malt is a critical ingredient in brewing - contributing sweetness, flavor complexity, body, and the characteristic color of beer - Rahr has a Technical Center & Brewery, located at the company’s headquarters in Shakopee. The facility includes a pilot brewery, micromalting laboratory, and advanced analytical labs, allowing Rahr’s scientists and brewers to conduct real-world brewing trials, analyze malt performance, and collaborate with brewery customers on product development and process optimization. 

Application Requirements

For its brewing operations, Rahr sought to improve control of the fermentation process, one of the most critical stages in beer production. During fermentation, yeast converts sugars into alcohol and carbon dioxide, and maintaining proper oxygen levels is essential for healthy yeast activity and consistent brewing results. 

Previously, Rahr used variable area flow meters to mechanically measure compressed air injection to increase oxygen content in the wort. However, to better support recipe development and improve process efficiency at its Technical Center brewery, the team decided to transition from air to pure oxygen injection.  In addition, Rahr wanted a more controlled and automated system.

Process Solution

To implement this improved oxygen control system, Rahr Malting partnered with process instrumentation specialists at William E. Young Company to identify a tailored solution capable of accurately measuring and controlling oxygen flow in a brewery washdown environment. The recommended solution was a Brooks Instrument SLAMf thermal mass flow controller equipped with a NEMA 4X/IP66 hardened enclosure, designed to withstand moisture and harsh cleaning conditions common in food and beverage facilities. The mass flow controller provides precise control of pure oxygen injection while enabling automation through integration with the oxygen sensor feedback loop. By incorporating an oxygen sensor that provides feedback to the oxygen injection flow controller, the brewery can precisely regulate oxygen flow and maintain optimal conditions for yeast fermentation.

 Photo Courtesy of Rahr Eagle Brewery 

With this system in place, Rahr is able to maintain consistent oxygen levels during fermentation, supporting more repeatable brewing trials and improved process efficiency within its Technical Center brewery. This level of process control allows Rahr to better support its customers by evaluating malt performance across a wider range of brewing conditions.

Rahr Malting is now producing repeatable and automated recipes by using the best technology and instrumentation. This innovation is enabling the company to become a world class brewer to ultimately create the best malt products to meet their customers needs.

UPDATE: This case study was mentioned in the February Tech Update of Food Engineering magazine by Wayne Labs.