No longer wasted off beer: Beer byproducts could be used for biofuels and food Beer produces a lot of waste, but it doesn't have to leave a bitter aftertaste. Amid the growing popularity of craft brewing around the world, brewers are starting to realize that beer produces a lot of waste. The waste byproducts of beer brewing are growingly becoming an environmental problem — but there might be an accessible solution to turn grain waste into protein sources and biofuel. Image credit: Flickr / Nicola Making beer involves malting, milling, mashing, boiling, cooling, and fermenting grain. About 20 kilograms of byproducts are produced for every 100 liters of beer brewed, 85% of which is brewer’s spent grains. Rich in cellulose, protein, amino acids, and minerals, some of the grains are used for cattle fed but most end up in landfills. That just won’t do.