Beer may be one of the oldest—if not, the oldest—beverage crafted by Man, after at all it is simply water added to yeast-fermented malt (grain) that has been flavored by hops. However, it was not until after the Industrial Revolution that it grew to be the massive global industry that we know it as today. Indeed, the invention of thermometer (in 1760) and then the steam engine (in 1765) and then the hydrometer (1770), gave brewers more control over the process, which improved both efficiency as well as attenuation.
The earliest beers were “top-fermented.” Basically, this means that during the fermentation process, the yeast would rise to the top to yield a thick, rich, “yeasty” head. Generally, fermentation of this type of ale yeast occurs at a relatively higher temperature (10 to 25 degrees Celsius) than “bottom-fermented” beers. Ales, Altbier, Kolsch-style, porters, stouts, and wheat beers (like Hefeweizen) are considered “top-fermented” beers.
A little more recently, brewers discovered that larger yeast strains will grow less rapidly at lower temperatures (between 7 and 15 degrees Celsius) with less surface foam, as they have a tendency to settle to the bottom of the fermenter as the process nears completion. The flavor of the beer will eventually depend on larger yeast strain as well as the temperature at which that strain of yeast was fermented. Bocks, Dortmunders, Marzen, Pilsners, (and American malt liquors) are all considered “bottom-fermented” beers. And since you are probably wondering: both Porter and Stout beers are “top-fermined” types, though; they are more malt-focused than their hop-heavy ale counterparts.
Now, you may have a specific type of Brutopia beer that you don’t see on this list. That is because classifications continue to get more and more refined as the art of beer making grows. Brewmasters research different types of malts and hops to find new flavor combinations. They also look for different ways to ferment the malt/yeast pairing for added complexity.
This is why ales are so popular these days. Ales can be more easily crafted and customized thanks to the availability of various hops from around the world. You can get hops from England, the United States, Germany, the Czech Republic, and even Australia and New Zealand.