A method for combined production of beer and a non-fermented beverage from grain material makes use of a by-product in the beer production to produce the non-fermented beverage and thereby improves resource-efficiency. The method comprises processing the grain material into a mash; separating the mash into a fermentable wort and a retentate; processing a retentate material into a slurry, wherein the retentate material comprises at least a portion of the retentate; separating the slurry into a liquid component and a solid component; processing the liquid component into the non-fermented beverage; processing the fermentable wort into the beer; outputting the non-fermented beverage; and outputting the beer.