The local beers were made with gruit, a herbal mixture that included among many other things bog myrtle. Historians are actually still looking for the entire recipe, if there has ever been one. The popularity of hopped beers made Dutch brewers turn to brewing this type as well, something the local count Willem IV hated it at first. He received 336917 tax over the gruit and now that this was being used less and less he ended the import of hopped beer. This lasted only two years and soon he reinstated the import, and gave Amsterdam the sole right to distribute it further over Holland and Flanders. He also levied a tax on hops, something Dutch brewers were increasingly brewing with. Fun fact: Jopen Bier from Haarlem used a local recipe from 1407 to brew a Gruit beer in 2000 and named it Koyt Gruitbier.  Today there are more than 50 breweries in The Neetherlands.