On average, big brewers product 7 to 10% of wastewater, also known as effluent, for every gallon of beer they brew. Among craft brewers, that number is closer to 3 liters of wastewater per liter of beer, and many craft brewers seek to reduce that number even further. Here are some of the techniques they are using to accomplish their goals of minimizing waste and reusing effluent in the beer-making process.
After the beer-making process, the wastewater contains high levels of organic compounds including spent grains or carbohydrates, sugars, yeast, and proteins. These solids would cause problems if they were dumped into the sewer system of most municipal water treatment plants because of the sheer amount of them that would enter the system.
