The malt we buy is partially germinated to encourage the endosperm to split the outer husk. We then mill the grain into chunky, Grape Nuts-sized pieces to increase the surface area of and access to the goodness held inside the grist.
Countless little Grape Nuts-sized bits of milled grain are mixed with hot water at a specific temperature to form a very thick, porridge-like "mash". This process activates the malt's natural enzymes that break molecularly "large" starches down into smaller, digestible sugars. The process also produces dextrins, which are unfermentable sugars that provide body and head retention to the finished beer.
After a period of mashing, the syrupy "wort" is run out of the bottom of the mash through a screen and collected in an intermediate vessel called a "grant". (We use our kettle.) The cloudy, particulate-filled wort is pumped back on top of the grain and recirculated until it runs clear and glassy.
Lautering and Sparging
The wort produced is then strained out of the mash ("lautered") into the kettle. Additional hot water is sprayed ("sparged") on top of the grain as the wort is run off, rinsing out a maximum amount of extract.
Boiling and Whirlpooling
When the kettle is filled to the appropriate level, the wort is brought to a violent boil and hops are added. The bittering compounds in hops (alpha acids) are not water-soluble and must be vigorously boiled for a period of time to chemically change (isomerize) them into water-soluble compounds (iso-alpha acids). However, long periods of boiling drive off the very volatile flavor and aroma compounds. Thus, bittering hops are added at the beginning of the boil and flavor/aroma hops are added near or at the end.
At the end of the boil, the wort is pumped very quickly around in a circle. When the pump stops, the centripetal force created carries free-floating solids (hops, precipitated protein, etc) to the bottom and center of the kettle creating what we call the "cone."
The settled wort is then cooled. The wort is run through a plate heat exchanger against near-freezing water that instantly drops the temperature to a yeast-safe level. The cooled wort is then pumped or "knocked out" into a sanitary fermentor.
Fermentation and Conditioning
A carefully measured, healthy dose of yeast is added ("pitched") to the fermentor. The yeast metabolize the malt sugars into alcohol (ethanol), carbon dioxide and a variety of flavor and aroma compounds. We use three different yeast strains and a variety of fermentation temperatures/schedules to precisely control the beer we are producing.
When the yeast have reached their threshold limit of digestion, they go into hibernation mode and start to settle out of the beer at the bottom of the fermentor. The yeast is still very much alive, and can be harvested and "repitched" into another batch of beer.
Some of our beers receive an additional hop charge directly into the fermentor, a process called "dry-hopping". The delicate aroma compounds in hops are adsorbed directly into the finished beer, creating an intensely fresh hop character.
The beer is then "crashed" to near-freezing temperature to help settle out remaining yeast, hops and other solids ("trub"). The beer is aged or conditioned for a long period of time to smooth out the edges and develop it's complexity.
Some of our brews are coarsely filtered to remove yeast from solution and produce a bright, brilliantly clear beer.
Carbon dioxide is gently bubbled through the bright beer and absorbed into solution, slowly carbonating the beer.