D. SCHLEEF (1), J. Grosser (2), R. Villas (3); (1) Pall Food and Beverage, Port Washington, NY, U.S.A.; (2) Stone Brewing Company, Escondido, CA, U.S.A.; (3) Pall Corporation, San Paulo, Brazil
Yeast, Fermentation, and Microbiology II
Saturday, October 10
Surplus yeast from the brewing process can contain a significant amount of beer that can be recovered and reintroduced into the brewing process. Depending on the brewing process and the dry matter of the harvested yeast, up to a 5% beer recovery or improvement of yield can be achieved. Ceramic membrane cross-flow systems have been used for more than 20 years to recover beer from yeast in the brewing process. These systems have been primarily utilized at breweries producing 1 million hL/year or more due to the relatively large system installation that was required to achieve an acceptable return on investment. Traditionally these systems were designed to recover beer from a mixture of yeast from multiple brands in a batch process, with recovered beer being added back into lower value brands. Craft brewers, on the other hand, are faced with a wide variety of beer styles across many brands. Depending on the beer type the recovered beers from surplus yeast require the return directly back into the source tank rather than blending a “composite” beer downstream or upstream that can be used in all brands. A direct return is only possible with a system that operates in continuous mode. Thus, the harvested yeast is directly processed and the recovered beer returned to the original tank. Furthermore, craft brewers tend to create more excess yeast and, therefore, more recoverable beer, due to the brewery design and product mix of the brewery. To solve this challenge, a new membrane design with double the surface area of traditional membranes was evaluated at Stone Brewing Company for both economic viability and organoleptic quality of the filtrate. This was achieved by using a full-scale pilot skid designed and operated by Pall Corporation, with beer analysis performed by Stone Brewing Company. Implementing this new design proved that it is technically and economically viable to design a system for recovering beer from excess yeast in a continuous manner that can reduce the extract loss of a craft brewery by 5% or more.
David Schleef has worked for more than 20 years for both small and large breweries and as a supplier to the brewing industry. After earning a diplom braumeister degree (diploma master brewer) from the Technical University of Munich-Weihenstephan in 1997, he commissioned and ran several start-up craft breweries on the West Coast, as well as working for Miller Brewing Company as a quality engineer. Since 2005 he has worked in numerous roles in the Food and Beverage Division of Pall Corporation, including his current role as brewing business development manager for North America, developing filtration and lab solutions for the brewing industry. He currently lives with his family in Oregon City, OR, and enjoys the outdoors, as well as traveling the world.