We do everything from scratch at Empirical, with flavor as our north star. Thus the processes we use are about the best possible ingredients, and layering different fermentations to create complexity and nuance.
Mashing is the first step in the brewing process for our spirits and cans. In a custom-built wet hammer mill that’s on a loop with our mash tun, the grains are ground with water and heated to fully convert the starches into fermentable sugars. When done, the wort (sugary liquid) must be separated from the undissolved materials.
Because we often use koji in our grain bill, the consistency of the mash gets extremely viscous and the only way to separate the wort is with a high-pressure mash filter. Instead of draining liquid from relatively intact malt through a single perforated plaque at the bottom of the tun, the mash goes through a series of 50 plates that will filter the wort and retain the solids. We finish the process with sparging (pushing water through the solids in the plates), allowing us to extract as much sugar as possible from the mash.
We constantly strive to improve our process and deliver the most flavorsome experience possible. That is why we slightly tweaked our brew recipe for The Plum, I Suppose. We originally mashed our Pilsner malt and barley kōji to create our wort.
To make our wash, we now brew our barley kōji with water and keep it at a temperature of 30°c. The addition of enzymes from White Labs helps further break down unfermentable sugars into fermentable ones. We then add our filtered Pilsner wort and yeast to ferment.
This process helps us capture even more the floral, fruity, and umami layers of kōji and make it shine in The Plum, I Suppose.
We worked with White Labs to access thousands of strains of yeast and optimize our selection for the flavor expressions we want the yeast to help create. While we are always experimenting with many of them, we set on Belgian Saison Yeast WL566 for our core spirits and cans. This strain contributes estery, fruity notes, and farmyard aromas to our wash. Our wort is transferred into tanks where it is top-fermented at 26 Celsius. If we hit it just right, the wash reaches 10% abv after a week, ready to be distilled.
We ferment our spirits slowly to produce layered, nuanced flavors. Fermenting each spirit multiple times - first in the kōji stage, then when adding yeast, and occasionally when we add things like distilled Kombucha at later stages - means we can achieve complexity and depth in each bottle.