2017 Master Brewers Conference
 
71. Supercritical CO2 hop extract improves brewery process yield over hop pellets

Michael Visgil, John I. Haas, Inc., Yakima, WA, U.S.A.

Coauthor(s): Victor Algazzali, John I. Haas, Inc., Yakima, WA, U.S.A.; Virgil McDonald, John I. Haas, Inc., Yakima, WA, U.S.A.

Poster
Hops

As the craft brewing industry seeks to become more efficient in brewing practices to improve process loss, the number of breweries that are considering CO2 hop extract as a substitute to hop pellets is growing. Anecdotal evidence suggests that using CO2 hop extract on the hot side throughout the boil process saves on overall beer production yields when compared to pellets under the same brewing conditions. To provide empirical support for this concept, we conducted two experiments to explore beer yield savings of Cascade CO2 hop extract versus different Cascade hop pellet products. Eight beers were brewed on a MoreBeer! direct-fire 15 gallon "single tier" brewing system to produce 8 gallon sample batches. The grist bill for these trials comprised 97% Pilsner malt and 3% acidulated malt. All beers were fermented at 20 °C using White Labs 001 California Ale Yeast. In the first experiment, we measured beer yield loss resulting from the absorption of liquid by hop vegetative material. Alpha acid content was not considered; instead, focus was on a weight-by-weight comparison of the hop samples. Four beers were produced following an aggressive hop dosage rate equivalent of 2 lbs/bbl hot side with Cascade T-90, T-45, and T-35 pellets, and Cascade CO2 hop extract. This approach allowed us to compare how certain amounts of hop vegetation relate to how much beer is absorbed in the kettle. Preliminary results show that with hop products compared on a weight-by-weight basis, Cascade T-90 pellets resulted in the most beer loss and Cascade CO2 extract resulted in the least beer loss in hot side applications. In the second experiment, we measured beer yield loss when factoring in alpha acid concentration of the Cascade hop products. Four beers targeting 40 IBU were produced to achieve 10 IBU bittering at 60 minutes and 30 IBU bittering at whirlpool using Cascade T-90, T-45, and T-35 pellets, and Cascade CO2 hop extract respectively. These products contained varying levels of alpha acid; as expected, a different amount of each product was used to achieve the final beer target. This approach allowed us to confirm that a hop product that contains more alpha acid results in less beer yield loss, because less of that product was available in the system to absorb the liquid. Preliminary results show that when comparing hop products by alpha acid concentration, Cascade T-90 pellets resulted in the most beer loss and Cascade CO2 extract resulted in the least beer loss in hot side applications. These findings suggest that as breweries seek to become more efficient in the brewing process, using CO2 extract offers an improvement over various pellet products as it pertains to beer yield savings.

Michael J. Visgil is a research and development scientist at John I. Haas, Inc., in Yakima, Washington—a member of the Barth-Haas Group. After graduating from Temple University with a B.S. degree in biology, Michael went on to complete the Intensive Brewing Science and Engineering Course at the American Brewers Guild in Vermont. He worked extensively in R&D for the flavor and extract industry in New Jersey prior to transitioning into his current role in the Pacific Northwest. He is humbled daily by the camaraderie, connectivity, passion, and expertise that the brewing industry has offered to him. In his free time, Michael enjoys experiencing the seemingly endless beauty of Washington and Oregon. When he isn't exploring, you can find him in his Ellensburg, Washington, kitchen obsessing over how to make great sourdough bread.

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