The Apex Predator of Beers
The playbook for opening a craft brewery is pretty simple. Get the doors open, then release a gosebier, kottbusser, and grodziskie. We followed this blueprint exactly, but only a few months in, we were struggling. We needed to come up with a new workhorse brand. “I think there’s a market for a hoppy saison,” said one particularly inspired John Laffler as he sipped on one of our lovely gosebiers. A hoppy saison made a lot more sense than the Beer for Tacos lime gose keg we blended for a summer event or the weirdo s’more imperial stout John was developing.
The first step was choosing the yeast, and a saison strain (supposedly used by Brasserie de Blaugies) had given John great results in the past. But controlling the flavor profile on a yeast that prefers to ferment warm (we cap our fermenters at 95 degrees F versus normal ale fermentation that typically maxes out around 70 degrees F), opens up a world of potential issues. But, when done right, fermentation with our favorite saison strain throws wonderful notes of ripe pineapple and juicy fruit bubblegum.
We backed the yeast-derived flavor profile with a hefty, short, and cold dry hopping of Crystal hops. Crystal hops combine notes old world (from its dad, Hallertauer Mittelfrüh) and new world (from its mom, Cascade) and are a perfect fit in our in our American-Belgo saison.
Unsure of the staying power of the brewery as a whole, I tried my first sip of our new saison, and experienced a sensation that everything was going to be okay. We shipping our first kegs after Thanksgiving 2013, and they started to hit draft lists in the second week of December with bottles hitting store shelves the following spring. Apex Predator is now our best selling beer accounting for roughly half of the volume of the beer we produce. It also is responsible for gobbling up around 75% of the total amount of hops we use as a brewery. Immaculately balanced flavor profile of ripe pineapple, juicy fruit, dry finish, and spicy, floral hops made a saison our flagship.
Ripe Pineapple
Esters are one of the most important components of beer flavor. They are highly volatile and greatly influence beer aromatics. Yet when asked to define them, most responses will center around German hefeweizen and its signature banana ester (isoamyl acetate). But with so many more different types of esters making up the critical flavors in all beer, they deserve a little more attention.
Esterification is a process in which yeast takes an alcohol molecule and an acid and mushes them together to create a new molecule through enzymatic activity. The amount of any given esters present in a beer will be determined by the amount of alcohol molecules, the amount of acid molecules, the enzymatic properties of the yeast, and the fermentation conditions.
Additionally, each ester has a different concentration threshold level humans can perceive. For example, ethyl acetate is the most common ester in beer but has a threshold of around 30 ppm (parts per million) to add a slight fruity aroma to a strong nail polish aroma to beer. While ethyl hexanoate will give an apple or anise aroma to beer in as little concentration as 200 ppb (parts per billion). For those of you without a billion fingers to count on, people can sense ethyl hexanoate at about a 0.6% concentration compared to ethyl acetate. The signature ester in Apex Predator is ethyl butyrate which gives off a ripe pineapple and tropical fruit aroma. Our saison yeast creates a high level of this ester which has a threshold of around 400 ppb or about 0.2 microliters (a microliter = 1/1000th of a milliliter) per can of Apex Predator.
Juicy Fruit
There came a moment, when I stood in front of two tanks filled with Apex Predator, one bursting with juicy fruit character and the other not so much. For a flagship beer, this type of inconsistency needs resolution. Fortunately, we had a fairly long log of taste panel notes. For those of you who don’t routinely do beer sensory analysis on an average weekday morning, taste panels consist of trained panelist tasting beer and scoring it based on various attributes. Several methods exist for scoring taste panels, but most involve a numeric score. This worked really well because we had a log of all the fermentation parameters, which are also almost exclusively numbers. And I was a quantitative methods TA in college.
The goal of my quantitative model was to maximize juicy fruit flavor taste panel score (the dependent variable) against the various fermentation parameters and see if I could isolate significant independent fermentation variables. After an afternoon of modeling, I achieved a model with a R-squared of 0.39 (meaning 39% of the change in the juicy fruit flavor was explained by my model). I had a statistically significant model forecasting a brew’s juicy fruit character based on the age of the yeast, the rate of fermentation (time before yeast is done fermenting) and age of the beer when sampled. The age of the yeast and the natural aging of beer in package are generally uncontrollable. But rate of fermentation is fairly easy to manipulate. As a result of this model, we reduced the wort oxygenation (yeast needs oxygen during the growth phase, when cells multiply and fermentation rate is at its peak). The result was Juicy Fruit Town, USA. We coincided this change with the switch to cans from bottles. Our canning line was promised to reduce packaged oxygen, which in turn would theoretically reduce the juicy fruit flavor loss during aging. From a marketing perspective, if customers were going to experience an improved Apex Predator, I wanted the narrative to be: “It tastes better out of the can!”
Dry Finish
Our favorite saison strain has some wild tendencies, literally. First of all, it is classified as Saccharomyces cerevisiae var. diastaticus because it carries the STA1 gene. The main challenge with diastaticus strains is the potential to ferment carbohydrates other common brewer yeast strain cannot ferment and result in over attenuation and gushing packaged beer.* Thorough attenuation works perfect for saisons and their signature dry finish. The saison yeast ferments about 74% of the sugars in Apex Predator wort (real attenuation), whereas a typical ale strain will ferment somewhere in the low 60% range. So less carbs!
Pitch rate (how much yeast is added to a brew) is one of the most crucial parts of beer making. For our brewers and yeast to get the yeast derived flavor profile correct, we have to nail the pitch rate. So as soon as we could afford a microscope, our brewers began counting our yeast prior to pitching into our brews to get a measure of how many yeast cells are present per volume of yeast slurry. The process required samples to be diluted because otherwise the yeast cells are so dense, they are impossible to count by eye. Almost all samples we count are diluted to about 1% slurry concentration prior to being inserted under the microscope. We dilute with a phosphoric acid solution that typically breaks down the cell walls and prevents the yeast from clumping together and becoming uncountable. But this saison strain does not play by those rules. It clumps together into clusters of hundreds (or thousands?) of cells that are virtually impossible to count. Our cell counts were so erratic, we just stopped doing it all together. Instead we measured biomass volume in a yeast slurry sample and once again looked at our fermentation data and made an estimated yeast cell concentration in a given slurry. Then we chose the estimates that gave the best results per the parameters of the juicy fruit regression model and used that one. So to this day, I have no clue what our exact pitch rate is. I just know the pitch rate is consistent and it results in the flavor we yearn.
Hints of Lemongrass and Pepper
After rubbing five or six different types of hops available at the time we were developing the Apex Predator recipe, John landed on Crystal hops coming out of Indie Hops in Oregon. Crystal hops are a hybrid of American and German hops, emitting both spicy and floral aromas.
Dry hopping is something we don’t do a lot, but our philosophy for dry hopping involves a large, quantity of hops pellets added to the fermenters after the beer has already been somewhat cooled and let the beer sit on the hops for a short period of time, 8 dC for one day and 0 dC for three days in the case of Apex Predator. This process pulls many of the subtler aromas out of the pellets, without overwhelming the final beer with an overly green, or grassy character.
The Lion
Coming up with the Apex Predator name was fairly easy. First, no other beer was named that yet, which helps. We came up with the Apex Predator name while wandering the halls of the Field Museum. We weren’t sightseeing, we were developing a new house beer for their upcoming Field Bistro and bar. Walking around the museum, we became awestruck by many of the alpha specimens. Sue and the man-eating Lions of Tsavo particularly stood out in a terrifying way. We pitched the name Apex Predator as it could highlight many different exhibits in the museum, but lucky (for us) they chose the name Tooth & Claw.
So instead of featuring various apex predators from The Field Museum collection, we went with just the lion. We liked to tell stories with our packaging, so the outside four pack carrier featured the lion (who went through several drafts) stalking a little mouse drinking a little beer. When you pulled the bottle out of the package, you’d find the insides of the lion contained the little mouse who was undeterred from drinking her beer. Unfortunately this drawing is not autonomically correct. We asked the Lincoln Park Zoo for actual X-Rays of lion insides, but we have yet to hear back..
- https://wyeastlab.com/resource/wyeast-lab-report-understanding-diastaticus/#:~:text=Diastaticus%20strains%20are%20found%20naturally,they%20carry%20the%20STA1%20gene.
