A recent study led by University of Arkansas Professor Dr. Scott Lafontaine and PhD student Andrew Maust, published in ACS Food Science & Technology, evaluated the sensory and chemical attributes of commercially available yeast strains used for nonalcoholic (NA) beer production.
Among the strains tested, Berkeley Yeast’s NA Classic and NA Cabana stood out. Panelists described NA beer produced by these strains as having flavor profiles with notes of tropical fruit, citrus, and subtle floral—qualities often sought in modern craft-beer styles.
More important was the distance between the Berkeley brews and those produced with some of the other NA strains. Whereas the Berkeley brews were generally associated with desirable flavor descriptors, some of the other strains were associated with less desirable characteristics such as plastic, cheesy, solvent, cooked potato, and wort—a greater departure from the flavor profiles that consumers enjoy.
The findings suggest that when designing or redesigning an NA beer recipe, strain selection plays a critical role.
Read the full (open access) paper here.
How the Study Was Conducted
Brewing Process
To conduct the study, variables were limited to isolate the differences among the different yeast strains and their sensory and chemical attributes. A simple wort was produced using 100 percent two-row malt and a small addition of iso-alpha acid extract to hit 10 IBUs (no hops were used throughout the process). Fermentations were conducted side-by-side at 20-liter scale, yeast was pitched at a rate of 10 M cells/ml, and all fermentations were held at a temperature of 68°F (20°C). Two different starting gravities were tested—4.5°P (1.018) and 9°P (1.036).
At terminal gravity, the pH was lowered below 4.2 using lactic acid (if needed). The beers were then kegged, pasteurized to 400 PUs, and subsequently chilled and carbonated.
Sensory Analysis
Ten trained sensory panelists assessed the beer samples in triplicate during six evaluation sessions. Before assessing beer samples, the panelists were trained over three sessions on 24 unique sensory terms for orthonasal aroma, retronasal aroma, taste, and mouthfeel. Three commercial beer samples were also used as flavor anchors.
During each sensory session, panelists scaled each of the 24 terms along a linear spectrum from “less intense” to “more intense.” The data acquired was used to generate a principal component analysis (PCA), whereby the different NA beer samples fermented with each strain were plotted alongside each sensory term. The results are shown in the figure at top. Note that the figure was modified from the original to include only fermentations that finished lower than 0.7% ABV, starting from 4.5°P (1.018) wort. See the original figure in the paper for additional data, including taste and mouthfeel descriptors and fermentations starting at 9°P (1.036).
In the figure, beer samples that are close in distance to a sensory term likely have shared qualities. For instance, NA Classic and NA Cabana map closely to tropical, citrus, and floral, while other strains map closely to such terms as cooked potato, dried fruit, plastic, and cheesy. The PCA provides an easy way to visualize similar qualities and groupings among samples and sensory descriptors.
The Bottom Line
Berkeley Yeast's NA strains were specifically bioengineered to produce NA beer that tastes more like actual beer. If you want to create a phenomenal NA beer, then NA Cabana and NA Classic can provide the foundation.
Want help designing an NA recipe? Please don't hesitate to reach out. We have a number of NA beer resources and a talented team of brewers experienced in designing NA beer who would love to help you succeed.