The brewing of beer has a long and rich history. The first known recipe is in a Sumerian hymn in 6 BC. Throughout its history, beer has been a local beverage; it was always produced near where it was distributed. This changed when prohibition killed most breweries. Unlike the wine producers of its day, who could make a meager profit through selling sacramental wine, the beer producers had to rely on unsatisfying near beer, malt extract, and other beer related products. When the curtain was lifted, the few remaining breweries, in conjunction with improvements in refrigeration technologies, were able to quickly grow to the national level. These new major brands focused on the most universally popular style of beer in the United States, American Light Lager. There has been a recent reversal in the trend of growing national beers, however, with the growth of the import beer market. This has fueled demand for now, more niche flavors than are available through the national brands. As such, many small micro breweries, also known as craft breweries have popped up. These small breweries are hampered by laws that exist in many states that require beer to be sold through the networks of the large national brands, but their popularity is growing. Microbreweries often produce niche or novelty beers. For example, there is a brewery that produces a beer from a strain of yeast that was dated back 45 million years.