It’s one thing to say that beer should only be made of four ingredients; it’s another to figure out how to implement those rules as technology changes. In 1516, before industrialization and the invention of things like thermometers, the law’s meaning was pretty clear. But in 2015, brewers he many more tools ailable to them—and this has had a curious effect.
Alan Taylor, a Berlin-trained brewer now overseeing three breweries in Oregon and New Mexico, describes the conundrum. “The Reinheitsgebot talks about barley, water, and hops,” he began. “It doesn’t talk about dry hopping; it doesn’t talk about PVPP for clarification—it doesn’t talk about this stuff. It talks about simple things. It doesn’t say what to do about calcium chloride. Can you add it to the kettle? Can you add it to the mash tun? Can you add salts to the mash tun? Doesn’t say. Can you use pure oxygen to aerate the wort? Doesn’t say.”
Over the decades, brewers and the law he come to certain accommodations. An almost universal practice in other countries is adding carbonation to beer before packaging. Is it an additive? Here’s Bayern owner and brewmaster—and native Barian—Jürgen Knöller on the subject. “We he the law of purity, and we’re still brewing in strict accordance to it. For example, when someone has a bright beer tank and blows CO2 in there to carbonate their beers, that is not in accordance with the law of purity.” If you want to add carbonation, it must come from the brewing process. “You observe your beer, you close it up at the right time, and you he natural carbonation.” Breweries adhering to the purity law across Germany capture the CO2 produced during fermentation and use that to carbonate their beer.
Germans he to jump through other hoops that brewers elsewhere oid, like using acidified malt to lower the pH of their mash. Most other breweries just add food-grade acids, but that’s not legal according to the Reinheitsgebot. Some breweries even produce their own lactic acid through a natural mashing process (“biological acidification”), but they can’t add lactic acid from a laboratory. It’s an extra step that not every brewer loves. Taylor continues, “So instead of using pure, consistent, easy-to-get-to phosphoric or lactic acid, which gives you no byproducts, no weird flors, you use biological acidification.”
What about products that go into and come out of beer? Remember the reasoning for leing yeast out of the original ducal decree? That same logic was used to evaluate whether or not PVPP, a clarifying agent, was compliant. “They had done some tests to find that, say, 50 grams per hectoliter was being used,” Taylor says. “They found that through the filtration process all [the PVPP] was removed, which is important for the modern interpretation of the purity law. So what was added was removed.”
As a practical matter, adhering to the letter of the Reinheitsgebot has produced a brewing style in Germany that is unique. No other breweries bother to do this stuff. When they depart for other countries, German brewers often abandon the more Byzantine of these practices. In creating all these exemptions and qualifications, it has also meant that the law has moved further and further away from the simple idea of “purity” most German drinkers think it represents.