Use of structured problem solving methodology to improve acid wash yeast process

Yeast and Fermentation Session
Sarah M Willis, MillerCoors LLC, Milwaukee, WI, USA
Co-author(s): Vince Coonce, Liana Turner, Amina Daar, Kamran Amini, Daniel Pearson, and Gustavo Charry-Parra, MillerCoors, Milwaukee, WI, USA

ABSTRACT: This poster illustrates the use of the DMAIC process for improving the consistency of acid washed yeast pH. A focused improvement team consisting of a cross-functional group of brewery employees looked for a sustainable improvement in the current acid washing process with the goal of removing the variability that can lead to poor yeast health or poor microbial control, and thus improve the quality of the yeast crop for pitching. Using a statistical model to determine the level of impact to the process, measurement of the effects of variables in the acid washing process (i.e., gauge R&R of instrumentation, acid-yeast contact time, variability of acid concentration, post-acid sample times) led to a review of operator SOPs and the procedure for determining the volume of acid used for washing. Improvements made to the acid washing process reduced post-acid addition pH variability.

Sarah M. Willis is a senior quality assurance engineer at the MillerCoors Milwaukee brewery. She holds a degree in chemistry from Alcorn State University in Lorman, MS, and has been employed with MillerCoors for 13 years.