Why Sensory Matters

image of beer in a beaker

Hundreds of different styles of beer, representing cultures from all over the world, ultimately come down to the same four ingredients: water, malted grain, hops, and yeast. This simple combination, along with subtle changes in time and temperature, can lead to astoundingly different results. In fact, minute difference in process or technique could cause the same recipe to yield unintended consequences.


For commercial breweries like Baxter, attempting to recreate the same final product each time can pose a challenge. One of the ways we attempt to keep the focus on consistency is by doing companywide sensory analysis on our finished beers.


“We have a product development benchmark sheet we try to follow. We try to call our shots, essentially,” says Merritt Waldron, Quality Director at Baxter Brewing.


“The less experienced of a brewer you are, the more qualitative recipe development is. What do I want it to look like? What do I want it to smell like? Is it modeled after a known style? I’ll challenge our brewers a little more to hit those target numbers. You need to hit your target Plato and know how much grain that’s going to take. Hit your IBUs and your final gravity with our yeast. We know our yeast inside and out.”


Once a recipe has been developed and a commercial scale batch has been produced, employees are asked to pour, smell, and taste beers which have been put aside to provide feedback.


While sensory panel results can vary in surprising ways, conducting them in an organized fashion helps the quality team at Baxter analyze the data in a useful way. We’re asked to look at color, foam, haze, and pick from a large list of smells and tastes. Mouthfeel, bitterness, and aftertaste are also rated. Compiling the results of sensory analysis from a dozen or so employees help to determine if we were able to deliver on the recipe as intended. The more specific the feedback, the more valuable the data.


Brewers yeast makes substantial contributions to the final aroma, flavor, and appearance of beer. The information gleaned from a well-organized sensory panel can give brewers immense insight into what happened during that fermentation.


Let’s take London Ale III, an extremely popular yeast used in making modern American IPA. If I have 14 participants rate the aroma of an experimental New England IPA, and they all tell me it smells “fruity”, that doesn’t give me much. But let’s say I give them a menu of aroma descriptors and ask them to list as many as they perceive. Eight people report aromas of tropical fruit, pineapple, mango and guava, one person puts grass clippings, one reports burnt match or sulfur, and four tell me that it smells earthy, rich or sour. That’s now extremely valuable information.


With enough data points, we can quickly eliminate the outliers, grass clippings and sulfur, and focus in on that compost smell. It’s well known that London Ale III can produce rotten fruit aromas, known as esters, when fermented at a higher temperature. Combine that with the fact that yeast produces heat during fermentation, and that sugar and mineral content from the mash are required for healthy fermentation, and the detective work begins.


Did I scale up my brewer’s salts precisely in line with my product development sheet for this batch? Have I recently calibrated my pressure gauges? How about pH? Some amount of variance is expected when developing a recipe, and taking the time to tease out the expected from the unexpected is time well invested.


“We’ve used sensory panels to subtly change ingredients. Sometimes we’ll do partial doses from one crop year of Cascade Hops in Stowaway to another, and we’re able to see how that changes our final product, because we have a very established True To Target profile for Stowaway,” says Waldron.


“Not everyone is going to pick them up, but to the people who are diehard Stowaway fans, if we just do a straight cut-off, from one crop year to the next, they might say ‘wait—what is this? I can’t quite put my finger on it but something’s different.’ We have a lot of dynamic tasters. The human palate really is a sensitive, fine-tuned instrument. We can taste and smell things in very small quantities that can be hard to measure in the lab.”


–Mike Polk

Production Team Member

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