Due to the sudden surge in popularity of craft beers, there might cause a shortage of hops. Craft beers require larger amounts of hops, and the varieties used in craft beers, "aroma" varieties, are less productive than bland high-yield alpha hops. By next year, acreage of hops growing will be changed to 60/40 in favor of aroma hops, while previously it was 70/30 in favor of alpha hops. Hop plants take several years to produce and at the moment, new breweries are opening up faster than hops can be grown, which will tighten the supply. A shortage has happened before in 2007, however "panic buying by hipsters might be premature. But small brewers may need to think further ahead or be ready to tweak their recipes".