Prussian king Frederick the Great was apparently very interested in the state of hops in Prussia. He noticed that most hops that Prussian brewers used in brewing was imported from surrounding hop growing regions like Bavaria, Franconia and Bohemia. Self-sufficiency was apparently an important economic principle at that time, if you could grow it locally it meant you didn’t need to spend time to import it from somewhere else.
So in 1743, Frederick the Great gradually ordered the various regions of his kingdom to start planting hop gardens and grow more hops: first Pomerania, then Saxony was ordered to become self-sufficient and if possible, export any surplus hops. In 1751, he ordered that experiments with Bohemian seedlings shall be undertaken in the regions of Altmark and Kurmark, as these hops were more popular on the hop markets due to “their greater strength and power”.
The Seven Years’ War stifled further initiatives, but in 1770, new orders were sent out to further promote growing hops for self-sufficiency. Hop poles were sold to new hop farmers for a very cheap price, and even a contest was started, with a cash prize of the farmer with the greatest hop production at the end of the year.
In 1775, hop gardens were introduced in Western Prussia, and the king’s chamber director was ordered to expand the hop gardens around Potsdam as the existing ones still couldn’t cover to demand from brewers in Berlin. In April 1776, imports into Prussia were completely prohibited due to a substantial surplus production of 2600 Wispel from 1775, about 1420 hecolitres in modern units (it is unknown whether this was in pressed or unpressed form), and enforcement of this law was supervised by the king himself.
There’s a story where allegedly Frederick the Great on one of his carriage rides through his kingdom noticed a carriage with a delivery of hops. Realising that from that particular street, it could have only come from Dessau, he suspected that the hops may have been smuggled in from the adjacent Principality of Anhalt. He immediately started an investigation that eventually found out that the hops were indeed contraband and illegally imported from Anhalt.
But the tides turned: due to a bad hop harvest in 1777, the king didn’t decide to allow imports, but he instead also forbade exports, to prefer the local market. And not just temporarily to deal with the hop shortage, no, this export ban was permanent, and the Prussian hop market was insular. Hop prices crashed, and by 1779, many hop farmers gave up the crop completely. The French period and the German campaign of 1813 didn’t help with developing Prussian hop gardens, either. Only in 1860, when Europe was hit by a terrible hop crop failure, Prussia had a temporary surge in new hop gradens: the Hallertau was the only region with a good harvest of high-quality hops, which sold for 6.5 times the normal rate. Farmers again started looking into hops as an attractive cash crop. By the end of the 19th century, much of the hop growing had shifted to Posen/Poznań, while both the acreage and the yield in the rest of Prussia steadily decreased: in 1898, Prussia only harvested a miserable 4.6 Zentner per hectare, while Bavaria reached 10.6, Baden 13.6, and Alsace 16.8.
If Frederick the Great had been more forward-thinking and less focused on self-sustenance, the current German landscape of major hop growing regions may have looked differently.