In Germany it is illegal to brew a beer with any ingredient other than malted grain, water, yeast, and hops. Apparently, April 23 is the day the law was enacted.
I do not know much about the law. Do you go to jail if you add honey to your wort? Does this law apply to home brewers or just commercial brewers? I do not know.
I do know that none of my home-brews pass muster with German Purity Law. All of my beers so far have a little something extra added for flavor or a boost in alcohol.
I will make sure my next beer is pure so that if any German guys come over I'll have something to serve them.
Happy Beer Day.