New York water tech company Xylem, in collaboration with Berlin water utility Berliner Wasserbetriebe and the Berlin Centre of Competence for Water, has developed “Reuse Brew,” a beer produced using treated and purified wastewater.

Recently showcased at the International Water Association (IWA) International Conference on Water Reclamation and Reuse in Berlin, the Reuse Brew was developed in part to highlight global water challenges, and as a model for addressing water scarcity with recycled water.

To sustainably turn groundwater into drinking water and eventually into Reuse Brew, water passes through Germany’s sewage treatment plants in a three- to four-step process. Following that, micropollutants like medical residues, biocides and other chemicals are removed from the water via a proprietary process called Oxelia, where ozone and activated carbon are introduced. At this step, ozone oxidizes the micropollutants and kills the bacteria and germs. Next, the activated carbon filters eliminate the substances oxidized by the ozone and eliminated by the microorganisms.

At this stage, the wastewater is considered to be of suitable quality and can be released back into lakes and rivers. Yet, to make the water suitable for drinking and making beer, additional treatment is necessary. Following the Oxelia process, water is filtered through yet another activated carbon filter, absorbing substances not eliminated by ozone or microorganisms. A reverse osmosis step then further improves water quality.

The final step for making wastewater safe to drink and thus usable in beer is called the Xylem MiPro process, which uses ultraviolet light and hydrogen peroxide to transform the wastewater into high-quality water.

"With additional treatment steps, we are taking wastewater treatment in Berlin to the next level using new, innovative technologies," added Regina Gnirss, head of research at Berliner Wasserbetriebe. "We will also continue to produce our drinking water sustainably from groundwater, because nature by itself also has immense purifying power. Here in Berlin, we know that water reuse can support the regional water balance, especially during dry periods."

Although the Reuse Brew is available in Germany for a limited time, Xylem has also partnered with the Pure Water Brewing Alliance, which is a group of utilities, brewers, engineering firms and technology companies brewing beer with recycled water, to eventually bring a recycled beer brand to the U.S.