Brewing a good-tasting non-alcoholic malt beverage is an awesome challenge for brewers. Some brewers experimented with special types of yeast. Others attempted to stop fermentation at just the right point. And still others tried to remove the alcohol from finished regular beer.
Clausthaler went up a completely new path. A patented brewhouse process based on the German Purity Law of 1516 ensures that little fermentable maltose is produced. Clausthaler Premium is then fermented with perfectly normal beer yeast that has been individually cultured for the brand. As there is little maltose available in the wort, the yeast can only produce a tiny amount of alcohol but it produces plenty of the full-bodied, flavorsome taste that characterizes a good brew. (from Clausthaler)