Using Reverse Osmosis to Treat Brewing Water

Reverse osmosis (RO) is sometimes necessary in breweries for two reasons. Firstly, if the source water contains undesirable contaminants like lead, RO acts as a positive barrier to remove them. Secondly, brewers may use RO to have ultimate control over water profiles, adjusting them for different beer styles. However, RO can be a wasteful process, as it produces concentrate that must be discharged. Traditional RO technology wastes one gallon of concentrate for every three gallons of permeate produced. A case study at Firestone Walker Brewery in California explored a solution involving a partial bypass of the RO system. By blending RO-treated water with a portion of untreated water, the brewery achieved greater efficiency and saved costs. The blending process required careful monitoring and control of key water quality parameters such as sulfate, alkalinity, chloride, and hardness. Through bench testing and assessment of brewing water and finished beer baselines, the brewery ensured that the final blend met quality and flavor standards. Additionally, considerations for microbial stability and the treatment of concentrate in the wastewater system were addressed.