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How the Yukon makes beer
Posted on December 29, 2006 at 2:09 PM in Product
The Mill
Whole kernels of malted grain are crushed between rollers, intended to reduce the inner endosperm to a fine grist while preserving the outer husk. Chilkoot ales start from whole, malted grains. Malting grains involves “steeping to germination” to release and/or develop the enzymes which modify the malt, and “kilning” to terminate the biological phase of malting.
The Mash Tun
The grist from the mill and water are mixed at a specific ratio and temperature. Chilkoot ales are brewed using an upward infusion technique, whereby the temperature of the mash is increased and held, three times, during the process. While this process is more cumbersome and costly than a downward infusion (mash at a higher temperature and let to cool on its own), it produces a more stable product with less haze and a better balance of fermentable and non-fermentable sugars.
Brew Kettle
The liquid from the Mash Tun, called the “wort”, is run off into the kettle. Additional water is run through the remaining grain bed, in a process called “sparging,” designed to leach out most of the soluble extract from the grain particles. The wort and spargings collected in the kettle are boiled to destroy any remaining enzymes, sterilize the wort, coagulate proteins, concentrate and darken the wort, and convert the hops which are added. Hops are added at various times during the boil to impart flavour, aroma and bittering.
Heat Exchanger
The boiled wort is run through a Heat Exchanger with ice cold Yukon water, both cooling the wort to a temperature suitable for the addition of yeast, and pre-heating water for the next brew. The flow of wort through the Heat Exchanger is adjusted for the proper exit temperature, and the wort is aerated with pure oxygen, priming it for fermentation.
Fermenter
When living, active yeast is mixed with cooled, aerated water, a series of effects is started that convert the wort into beer. Simply stated, fermentation involves sugar and yeast “in”, alcohol, carbon dioxide and heat “out”. As soon as end fermentation is completed, the beer in the fermenter is chilled to near freezing and allowed to age. From here it is bottled and send out to the store.
Duel Filters
Chilkoot Ales are double-filtered: The primary filter is a Diatomaceous Earth, or D.E. Filter. Diatomaceous Earth is made up of the silica skeletons of small fossil marine organisms. Under a microscope, this appetizing-sounding material looks like swiss cheese. It filters by catching the larger pieces in its holes.
The secondary filter is a plate and frame style filter, filtering the beer to 0.5 microns - virtually sterile. This produces a brilliantly clear beer free of bacteria, extending the shelf life without pasteurization.