Tuatara brew true to style, so wherever possible they go direct to the source and use ingredients that have made that style famous. It says Bohemian Pilsner on the bottle not because it reads poetry and plays the bongos but because that’s where the yeast is from.  And of course everything is created using nothing but yeast, malt, hops and water, the regime the Bavarians call Rheinheisgebot and have been enforcing since 1516 in the way Bavarian regimes tend to be enforced.