Comments by "Evan" (@MrEvanfriend) on "The Fall of the House of Lemp, a St. Louis Brewing Empire" video.

Lager is not necessarily lighter. You can make heavy, dark lagers just as easily (in fact, more so), than light, pale lagers. The difference between lager and ale is in the yeast - lagers use a different species, Saccaromyces pastorianus as opposed to S. cerevisiae. Lager yeast ferments at much cooler temperatures than ale yeast, and lagers are then "lagered", or cold stored, for a period. This results in a "clean" fermentation flavor, without the fruity character that ale yeast will give to a beer. It is also a harder brewing process that requires much more control over the temperature during fermentation.
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