Fusing Craft and Science
Cold vacuum distillation removes nearly all of the oxygen and atmospheric pressure from the distilling system, which allows liquids to boil at temperatures far below their normal boiling points.
Why Cold Distillation?
Preservation of Flavor
Distilling techniques evolved hundreds of years ago, and haven't changed all that much since the column still was invented over a hundred years ago. But distilling under vacuum allows us to preserve fresh flavor and character otherwise altered or diminished by both the heat of distillation and chemical reactions in the still at these temperatures.
It All Starts With an Idea and a Beer
Each spirit begins with a flavor profile that we want to achieve. We then work out a beer mash recipe with particular malts, yeasts, and even hops and fruits or other natural flavors in the fermenter. A beer is then mashed, boiled in a kettle (or not), put in the fermenter, yeast pitched, dry hops added (or not), and allowed to ferment for as long as it takes (usually a week or two).
Importance of Ingredients
Good In, Good Out
A great recipe is nothing without great ingredients. We hand select all everything that goes into our whiskey mashes or gin infusions, from the grains to the fruits and botanicals. Whenever possible, we select the freshest possible items because you can't create something wonderful if you start with something less than.
Leveraging the Wonder of Fermentation.
The sheer variety of yeasts available to us today is remarkable. Most distilleries prefer to work with yeast types that work fast and furiously to pump up the alcohol in their mashes. We take a different approach. Working with the wide variety of beer yeasts available, we select yeast that generate flavors complementary to those of the planned spirits. If it takes a month, such as with a pilsner, so be it. This is a step that takes time to develop flavors, and because we can preserve them with cold distillation, it's a departure from traditional methods wherein the barrel is responsible for much of the flavor development.
Distillation Under Cold Vacuum
Preserving Fresh Flavor
Distilling ethanol at atmospheric temperature means distilling in the range of 175-195F (79-91C). After pulling a strong vacuum on our continuous column still, we are able to distill between 60-90F (16-33C). The benefits include preserving delicate and fresh flavor character, preventing thermal degradation of flavors and limiting chemical reactions that often take place in a still. The kinetics of chemical reactions generally double for every 10C rise in temperature. Vacuum allows us to limit these reactions to less than 1% of what would occur at normal distilling temperatures. An additional benefit is that sulfurous compounds are far less likely to distill over with ethanol under vacuum, meaning copper is not necessary.
What does all this mean? The liquid out tastes and smells much more like the liquid going in. Cleaner, fresher, and with less burn or contaminants.
To Barrel Age or Not to Barrel Age?
Why Not Do Both?
Post-cold distillation, hard choices must be made. For our vacuum distilled spirits, the choices depend on the end goal. When we distill a hoppy beer, the white spirit may be perfect as it is. In this case, we may not age it at all. If it's something intended for wood aging, like a high ABV stout or whiskey mash, then we may barrel it or put it in vessels with wood chips, like oak, maple or cedar, to age. Or both! The only limit is our imagination.
Normally we'll do a whiskey and age it different ways for different experiences. Maple lends a syrup character that makes for great old fashioneds, applewood can lend a fruity character and light tone great for summer whiskey drinks, etc.