The Egyptians created zythum, a beer-like beverage made of malt and wheat, after manipulating the process a bit. The ancient Egyptians and Babylonians started cultivating grain around 6000BC and discovered the fermentation process by accident. These crude alcoholic drinks were also used as currency in ancient Egypt before being snuffed out by the spread of Islam around 800AD. Early traces of the brewing process have been found in ancient Babylonia as well. At the time, brewers were women as well as priestesses. Some types of brews were used especially in religious ceremonies.
The process of brewing grew tremendously during the rise of Christianity. This was primarily because of the roles that monks had in the production of beer. Monasteries were some of the first organizations to brew as a trade. Monks built breweries as part of their efforts to provide food, shelter and drink to various travelers and pilgrims.By the 15th century, German brewers started using hops to flavor and preserve their "ales". An unhopped brew would have been known as an ale, while the use of hops would make it a beer. By the 16th century, "ale" had come to refer to any strong beer, and both types were hopped. Brewers in Bavaria began storing their brews in cool caves to prevent spoilage. This type of beer became known as lager, from the German word lagern, meaning "to store" and the discovery of bottom fermented brews. They have since largely outpaced top-fermented brews in terms of volume.
Following significant improvements in the efficiency of the steam engine in 1765, industrialization of brewing became a reality. Further innovations in the brewing process came about with the introduction of the thermometer in 1760 and hydrometer in 1770, which allowed brewers to increase efficiency and attenuation.
The invention of the drum roaster in 1817 by Daniel Wheeler allowed for the creation of very dark, roasted malts, contributing to the flavour of porters and stouts. Its development was prompted by a British law of 1816 forbidding the use of any ingredients other than malt and hops. Porter brewers, employing a predominantly pale malt grist, urgently needed a legal colorant. Wheeler's patent malt was the solution. Many European nations have unbroken brewing traditions dating back to the earliest historical records. Beer is an especially important drink in countries such as Belgium, Germany, Austria, Ireland, UK, France, the Scandinavian countries, Poland, the Czech Republic, Spain and others having strong and unique brewing traditions with their own history, characteristic brewing methods, and styles.
In the U.S. prior to Prohibition, there were thousands of breweries in the United States, mostly creating heavier brews than modern U.S. drinkers are used to. Beginning in 1920, most of these breweries went out of business, although some converted to soft drinks and other businesses. Bootlegged brews were often watered down to increase profits, beginning a trend, still on-going today, of the American palate preferring weaker beers. Consolidation of breweries and the application of industrial quality control standards have led to the mass-production and the mass-marketing of huge quantities of light lagers. Advertising became supreme, and bigger companies fared better in that market. The decades after World War II saw a huge consolidation of the American brewing industry: brewing companies would buy their rivals solely for their customers and distribution systems, shutting down their brewing operations. Breweries and imports have become more abundant since the mid 1980s; the number of breweries has been claimed as being either over 1,500 in 2007 or over 1,400 in 2010, depending on the source.