Just because something is fun to do, doesn’t mean there isn’t a robust science involved. Case in point: beer sensory. My relatives like to joke that they also studied beer sensory in college, but I think the readers will be aware of the difference between running a carefully randomized tetrad test and doing a keg stand on a football player’s front porch. To properly conduct the science of beer sensory, you start by finding 16-or-so willing participants (shouldn’t be difficult) to undergo rigorous beer flavor training and validation. Through this training and validation, you ensure that everyone is speaking the same flavor language, describing specific flavor-active compounds in agreed-upon terms.
While technology has come a long way in helping us describe the chemical reactions taking place on brew day, quantitative data from analytical equipment falls short in describing the sensory experience of drinking a given beer – good news for your 16-or-so panelists. The human nose is capable of detecting millions of aromas, and more importantly, humans are capable of linking these aromas to incredibly specific real-world objects like guavas or jasmine flowers. It’s an impressive feat, and in this particular battle of Human vs Machine, we’re winning.
Beer Sensory in a Hop Context
Beer sensory is important to the industry, but it’s far too time consuming and resource intensive to assess every lot of hops during harvest this way. Enter: hop sensory. The process of gathering and training panelists is similar to that of beer sensory, but the results are produced a lot faster; thousands of samples can be assessed within a harvest period. This allows for ruined harvest lots to be eliminated from the get-go before expensive resources go into processing them. Hop sensory produces a clear snapshot of different varieties from different growers, harvested on different days, so that brewers participating in hop selection can get exactly the product they’re looking for each crop year. Using this data, we can reveal how the sensory characteristics of each variety are evolving over time.
However, due to thousands of reactions that take place during brewing, the key aromatic compounds identified in hops have undergone many changes by the time they make it into the final product, if they even make it at all. When brewing, hop compounds are modified by thermal reactions, yeast biotransformation, chemical conversions such as oxidation/reduction, hydrolysis, isomerization, ester exchange, and even evaporation. During fermentation, for example, yeast metabolic activity will biotransform geraniol (a bed of roses) into β-citronellol (zesty lemon), completely changing the aroma characteristics of the beer. So, it’s not only necessary to apply sensory to hop aroma, it’s vital to also focus on the aroma compounds present in the end product – the beer brewed with these hops, to fully understand which hop characteristics are of the greatest importance to brewers.
To complicate matters further, brewing components like malt and yeast contribute to flavor in varying degrees depending on the beer style, and hops contribute non-aroma characteristics to beer such as bitterness, mouthfeel, and haze, all of which are important to monitor and assess in order to fully understand a hop’s full contribution to beer.
Benefit to Growers
Hop growers are beginning to identify the specific genes responsible for producing certain flavor compounds and can use beer sensory data to zero in on the ones that actually make it into the final product.
Beer sensory assessment acts as a helpful stage in filtering through the thousands of experimental varieties that breeders develop to determine the lucky few that will be planted on a large scale and eventually released to the public. The whole process of new varietal development takes upwards of 12 years, with only one in every 10,000 new hop varieties ever making it to market. This lengthy, arduous, and resource heavy process relies on sound assurances that beer drinkers will embrace a new hop, in turn giving brewers a reason to welcome it onto their brewing schedule.
At the other end, when growers wish to tweak production to increase efficiency, beer sensory can make sure that any changes have not negatively impacted sensory attributes of the final product. From optimizing harvest windows to dialing in the perfect kiln temperature, growers use beer sensory feedback to guide the decision-making process.
Benefit to Brewers
Brewers ask a lot of questions. How do I get my beer to taste like starfruit? When in the process should I add hops to achieve a perfect balance between fruity and bitter? How will dry-hopped beer behave over time in different storage conditions? Answers to such questions are critical for success, but not all commercial brewers have the luxury of committing precious resources to pilot brews in order to find them. Beer sensory scientists can glean important information from brewing the exact same beer multiple times, tweaking only single aspects (like hop variety, hop addition timing, or storage conditions). The results of sensory analysis on these experiments can be passed to brewers, saving them time and capital, and optimizing the quality of their outputs.
The results of beer sensory studies also help brewers by guiding hop blend development to meet specific market demands. For example, an additive effect has been found to exist whereby the coexistence of linalool, geraniol, and β-citronellol creates a strong flavor impression of lime – crucial information in a time where citrus flavors in beer are fervidly sought, making access to hop products developed using this information incredibly valuable.
To put it simply, brewers just want to make good beer that people like, and sensory assessment is one weapon in the arsenal that can be used towards that goal.
The Circle of Sensory
Hops growers, brewers, and the beer market are linked in a never-ending feedback cycle. Growers develop and produce a hop variety, brewers use it to make the best beer they can, and the market lets us know what they think with their dollars. That information gets passed back to growers, who can adjust according to what the people want.
And the stitches linking this whole process together? You guessed it. Beer sensory.
Written by Tessa Schilaty, Sensory Coordinator at Yakima Chief Hops
At Yakima Chief Hops, we have invested in a robust hop and beer sensory program, dedicating time and resources to gathering this valuable information in-house that we then share with our industry partners. Trained YCH staff members from all areas of the company meet regularly to taste, sniff and evaluate various beers and hop varieties with the guidance of our own Technical and Brewing Innovations teams. Drinking beer is a tough job, but our employees are happy to take one for the team!