The 19th century brought a flurry of new breweries and maltsters (who sold that crucial ingredient, malt). And here the book gets a little soporific, what with the litany of whozits and how many barrels a year they produced. But if you throw one back and keep reading, you get to the effects that technology wrought on the industry, which are of interest. In 1891, William Painter invented the Crown Cork Bottle Closure, which allowed for a tight seal on bottled beer, retaining flavor and carbonation. (The Crown Cork and Seal plant building still looms over Greektown.) The American Can Company, another Baltimore company, successfully canned the first beer in the 1930s. This allowed beer to be shipped overseas to soldiers and sailors during World War II. When they came back, they had become accustomed to this lighter stuff made at national breweries rather than the richer craft-brewed varieties, which helped lead to the demise of the smaller breweries.