Alyce Hartvigsen, Alfa Laval Copenhagen A/S, Soeborg,
One of the achievements of the rapidly growing craft brewing sector has been the introduction of aromatic, dry-hopped beer varieties to an increasingly large segment of beer drinkers. As more "mainstream" consumers acquire a taste for these products, the demand for dry-hopped beers continues to explode, and many larger breweries have begun to implement the practice. However, there are a number of process challenges associated with the automation and scale-up of dry-hopping techniques in larger breweries. These include introduction of the hop pellets into the fermentation/maturation tanks without excessive oxygen pick-up, effective extraction of the aroma compounds into large volumes of beer, removal of the hop particles from the product while minimizing product loss, and efficient CIP of the system. While a number of commercial dry-hopping solutions have been offered in recent years, most exhibit capacity limitations (i.e., not suitable for large volumes or tanks), are difficult to clean by automated CIP process, and are challenging to integrate into automated modern breweries. The potential of rotary jet mixers for dry-hopping applications has been considered, but the high particulate loads in the fluid require a special mixer design. To address the needs of this growing market, we have developed a new type of Rotary Jet Mixer system to tackle the challenges of dry hopping larger beer volumes with minimization of oxygen pick-up, minimal beer loss, and full cleanability. The strong jets of liquid homogenize hop aromatics throughout the entire beer volume, thereby potentially reducing the required quantity of hops while still attaining the desired flavors in the beer. Homogenization of the hop particles continues during transfer to downstream centrifugation, thereby improving the separation efficiency and product clarity. The system is easily automated and gives considerable flexibility in the method of hops introduction to the process. The standard configuration of the installation is similar to the conventional Rotary Jet Mixer system, and consequently is also suitable for use in the fermentation, maturation, and crash-cooling processes. This presentation examines the particular challenges of dry hopping on a large scale and demonstrates how the new system can uniquely address these challenges, thereby allowing larger breweries to produce tasty hoppy beers using an elegant, efficient, and economical dry-hopping process.
Alyce Hartvigsen was born in Philadelphia, Pennsylvania, in 1967 and completed her B.S. degree in chemical engineering at Case Western Reserve University in 1988. She began her career in process engineering in the petrochemical industry. In 1994, she accepted a technical sales position with a Danish technology company in Houston, and moved to Denmark in 1997. Her arrival coincided with the beginning of the craft beer "revolution" in Denmark, and over the years she developed a keen interest in beer and brewing, joining the Danish Beer Enthusiasts and a home-brewing club. In 2012, she took advantage of a unique opportunity to combine career and personal interest and joined Alfa Laval as sales and technology manager in the brewery market unit. Here, she is responsible for the global sales and technical support for rotary jet mixers and other tank equipment in the brewery market. Her work has primarily focused on developing and promoting applications for rotary jet mixing in the brewing industry. She has overseen the implementation of both commercial-scale trials and full cellar installations, and works closely with the end-users in the commissioning and process optimization of the systems. Planned activities include expanding the applications for rotary jet mixing within the fast-growing craft brewing sector.