While many won't witness firsthand the ladies in dirndl or drink the foamy pints of beer at Munich, Germany's great Oktoberfest, all can learn about lager, a popular style of beer that originated in the country's Bavarian region. Before we get into how to spot a lager, let's start with some brief history. Germans started fermenting lagers only a few hundred years ago — that's relatively new compared to ale. The word originated from the German word lagern, which means "to store," since lagers are fermented and then stored in a cool cellar for several months.

Lagers differ from ales in several ways: in yeast used to ferment the brew, the time it takes to ferment, and the storing temperature. Ales require a top-fermenting yeast that is activated at room temperature and ferments for a quick seven days. On the other hand, lagers call for Saccharomyces pastorianus, a bottom-settling yeast that ferments the water-malted barley mixture. Lagers ferment slowly in cooler temperatures over a longer period of time (several weeks, or even months), which is said to contribute to the mild, mellow flavors and clear, rather than cloudy, composition.

Find out how you can detect a lager by smell and taste when you read on.

Beyond the fermenting method, the appearance, scent, and taste are the most obvious ways to distinguish an ale from a lager. If the beer appears clear, is served very cold (not just under room temperature), and is visibly fizzy, chances are it's a lager and not an ale. But after eying the glass, use your sense of smell. A lager should have a slight sulfuric scent (a normal characteristic for lagers) but otherwise should smell clean. Any detection of a robust, hit-your-face fruity aroma, then the beer may be an ale. Lastly, take a sip. If it's mellow (not bitter), light-bodied (not heavy-bodied), and crisp and clean (not fruity and herbaceous), then — ding ding ding — the beer's probably a lager.

Wondering who makes some well-known lagers? Beck's, Heineken, Sapporo, and Budweiser are all common beers that just so happen to also be lagers.