Point-of-Entry (POE) Water Treatment Used for Chlorine Removal in Microbrewery Application
Summary: RO is the preferred technology for many commercial/light industrial applications where feed water purification and final product water consistency are essential. Growth of U.S. microbreweries has created an opportunity for this application. The following case study offers an additional area of interest in that the feed water to the microbrewery is product from a local municipal RO plant.
'As Seen in Water Conditioning & Purification'
POE Applications for a Microbrewery
Beer, by definition, is an aqueous solution, 91-to-97 percent of which is water. The importance of water quality in beer production cannot be understated and was the driving force behind consideration of a particular reverse osmosis (RO) water purification system for brewing.
The Outer Banks Brewing Station, in Kill Devil Hills, N.C., is a microbrewery with a projected need of up to 3,000 gallons per day (gpd) of purified water to support production of 500 gallons per batch of its brewed products. A microbrewery is a brewery that produces less than 15,000 barrels (17,600 hectoliters) of beer per year. Raw water supplied to the microbrewery from the local municipal RO plant lacks the quality and consistency needed for optimal brewing.
Importance of water source
Long before the water chemistry behind the brewing process was scientifically understood, great breweries sprang up in the proximity of excellent water sources. If the local water source was inadequate for proper brewing, the beer produced would be of poor quality. Either the brewery moved to a better source of water, adapted their brewing techniques, or they perished.
Water profiles from the classic brewing regions are surprisingly different from each other, accounting for the evolution of unique beer styles from those areas (see www.barandbeer.com or www.ebraumeister.com for beer types). It was the early trial and error compensating methods in addition to the presence of certain mineral ions that determined the style of beer that evolved from an area. When certain Munich brewers moved to Prague, they were amazed at how light and delicate their beers turned out from essentially the same recipes and ingredients used in Munich.
What's most important to the brewer is the effect the brewing water has on mash pH. Malt enzymes are very particular about temperature and pH, and mashing is essentially an enzymatic process. Proper mash pH, usually preferred at around 5.2-5.4, can be achieved by several means. In the early days of brewing, methods were mostly limited to malt composition and biological acidification. Modern breweries may add food grade acids such as lactic acid or phosphoric acid to adjust the mash pH.
London water is high in carbonate ions, which tends to drive the mash pH up, but dark roasted malts acidify the mash and the balanced pH results in excellent porters. North of London in an area called Burton Upon Trent the water has extremely high levels of dissolved minerals, especially gypsum, which lowers mash pH, thus enabling a balanced mash with minimal dark malts resulting in exceptional pale ales.