23. Improving brewhouse efficiency by adjusting mash water, lauter, and sparge volumes

Eddie Gutierrez (1), Drew Russey (1); (1) Saint Arnold Brewing Company, Houston, TX, U.S.A.

Technical Session 7: Brew House Operations
Monday, August 15  •  8:15–9:30 a.m.
Tower Building, Second Level, Grand Ballroom

Increasing brewhouse efficiency is relevant to breweries of any size and model. Making simple process adjustments can result in lower raw material usage, as well as save time and money, without decreasing quality. Brewhouse efficiency improvement often focuses on the treatment of the raw ingredients, namely grist and water profile, to attempt to increase efficiency. This study demonstrates how varying water and wort volume throughout the mash, lauter, and sparge processes can improve brewhouse efficiency without increasing lauter time. Mash in liquor volume and pre-sparge/post-sparge wort lauter volume are studied independently to determine their direct effect on brewhouse efficiency. First runnings, final runnings, lauter time, and target volume are response variables used as indicators of the success of each experiment. Initial findings from the independent experiments were promising, so we combined experiments to look at the aggregate effects of successful cases and decrease grain bills where needed to keep our batch sizes appropriate for fermentation vessels. The study focuses on two general mash/lauter techniques used by Saint Arnold Brewing Company (SABC) and many other breweries: single-mash and double-mash brewing. Single-mash brewing uses one mash/lauter per batch produced. For this technique, this study focuses on beers that have final runnings higher than 2°P, common in beers with original gravities 16.5°P and higher. The goal was to extract more of this quality wort and get the final runnings closer to 2°P, which is our lower limit. The double-mash method is used to produce our high-gravity (23°P) beers, which traditionally have no sparge and require two mashes and lauters to get to boil kettle full volume with gravity close to 23°P. The limitation in this case is the lauter tun size. Even with splitting the batch, the grain bed usually collapses and must be completely regenerated, sometimes multiple times per lauter. The goal for this technique was to prevent grain bed collapse and reduce lauter time, while maintaining target volume. All experiments for both techniques are conducted on a 136 bbl BrauKon refurbished brewhouse with BrauControl logic and automation. Each initial experiment, and each adjusted general mash/sparge technique, is compared to all unaltered batches of the same beer from the previous year. Statistical analyses between adjusted batches and controls were performed using either a t test, or a non-parametric equivalent Wilcoxon rank-sum test when normality assumptions were not met. Sample sizes for the comparisons consisted of at least 3 batches in the initial experiments and at least 8 batches in the general mash/sparge techniques. This study demonstrates that varying water and wort volumes during the brewing process had an effect on both brewhouse efficiency and lauter time. Successful combined experiments were adopted as the standard for our brewing processes.

Eddie Gutierrez received an M.S. degree in mechanical engineering from New Mexico State University. His focus of study and thesis involved porosity and permeability of oil reservoirs and microseismicity, respectively. He worked as a design and efficiency engineer at Schlumberger from 2012 to 2014. In January 2014 he was hired as a brewer at Saint Arnold Brewing Company. In 2015 he was promoted to lead brewer and has spent the past year focusing on brewhouse optimization.