Archaeologists have turned up evidence that the Sumerian people in the Middle East were brewing barley as long as 8,000 years ago. These early brewers may have discovered the fundamental processes of brewing as they observed—or tasted—what happened when they left fruit juices or cereal extracts exposed to the wild yeasts that naturally float in the air. Native Americans made a beer from corn, which they softened by chewing and mixing into a pulpy mass with saliva. They then set this masticated corn out in a vessel to ferment, and enjoyed the resulting drink.
Throughout Europe, breweries sprang up where there was good water for brewing. During the Middle Ages, monasteries became the centers for brewing, and the monks originated brewing techniques and created many of the beers still popular today. Early European settlers in North America brought with them from Europe a taste for beer, but followed the Native Americans' example and initially made beer from corn and pumpkins, which they flavored with such local additives as the tops of spruce trees.
With the spread of the British empire and rise of industrialization over the past 150 years, traditional European beer began to move from its local markets to towns, pubs, and countries far away from its place of origin. This emigration was aided with the introduction of bottled beer in 1875 by the Joseph Schlitz Brewing Company in Milwaukee, Wisconsin, and the later advent of canned beer in the 1930s.