Next time you sit down and enjoy an adult beverage, be it fermented or distilled, don't toast your friends, family or colleagues. Instead, direct your praise and goodwill toward the fungus to which man is most indebted: yeast. It is this microorganism that is responsible for your merriment and that newfound vigor in your dance step.
The glorious transformation of fruit or grain into alcohol is made possible by this unicellular marvel of nature. When fruit is pressed or grain is mashed, a sweet liquid is created, providing the perfect food source for yeast. Fermentation occurs as the yeast propagates and eats available sugars, in turn producing carbon dioxide and, of course, ethyl alcohol.
Though beer is not the only beverage fermented by yeast, it is probably the drink with the most interesting relationship to our fungal friends.
Contrary to popular belief, ale and lager are not styles of beer but rather two general beer groupings, determined by the type of yeast used in the brewing process. Ale yeast does its work at the top of a batch of fermenting beer and at warmer temperatures, while lager yeast is bottom-fermenting and prefers cooler environments.
Aside from this zymurgical difference, there are flavor consequences for the type of yeast used. In addition to alcohol and gas, the fungus produces various compounds, which can provide interesting flavors ranging from fruity and herbal to clove-like and even buttery. Ales tend to be fruitier and more complex than lagers, which are generally more crisp and smooth.
British and Belgian beer best characterizes the ale category, whereas German and Czech beers are more likely to be lagers. There is also a great deal of geographical variety in yeast strains, and because of this, no two beers are exactly the same, even from the same region.
Taking a walk on the wild side, I give you yet a third category of beer based on yeast-type: lambic. Also referred to as wild ale because of the use of wild yeast, lambic beer can take a variety of forms, most of which are traditionally brewed in Belgium.
The lambic brewing process is unlike that of any commercial or craft brewery. Instead of having controlled, cultured yeast, a lambic brewer allows his wort—brewed beer before alcohol—to ferment in open containers, inviting all kinds of funky fungi to the party. This technique is called spontaneous fermentation, and the result is a beer with a unique flavor profile that is tart, sour, funky and fruity, but also very refreshing.
Revered among beer enthusiasts, lambics are unfortunately somewhat difficult to find in normal beer stores, although The Lion's Pride (a new Brunswick bar and restaurant featured in one of my previous columns) will surely have some sour bottles and maybe even a Kriek or two on-tap.
Yeast. Who would have thought this simple little organism would have such an impact on beer, and, concomitantly, society? I hope this article helped cut through the confusion surrounding ales, lagers and lambics, in addition to providing a new understanding of our fungal friends: feed them, and they make alcohol. Brilliant! Here are a few brews that I feel represent the ale, lager and lambic groups well.
Pilsner Urquell
Pilsner is the style of beer that American macro lagers so half-heartedly imitate. The real thing is a crisp, bitter and refreshing lager, with a great hop aroma usually due to the use of Saaz hops. Germans brew excellent pilsners, but the original hails from the Czech city of Pilsen and is called Pilsner Urquell. You can find it in the bottle in the United States, but, speaking from experience, Pilsner Urquell takes on a completely different meaning when had on-tap in Prague.
Anchor Steam Beer
Steam beer is one of the two indigenous American styles of beer, the other being cream ale. Crafted in San Francisco, Anchor Steam is an interesting hybrid example of ale and lager brewing techniques: this beer is brewed with lager yeast, but at ale temperatures. The result is a unique brew, exhibiting a partially hoppy and slightly malty flavor, with a lively, effervescent mouthfeel.
Old Speckled Hen
Aside from having one of my all-time favorite beer names, this British ale is an excellent representation of the English Bitter style. All traditional British beers are ales, but that does not mean there is a lack of variety in British beer. As the name implies, this style is bitter, but not astringently so. Old Speckled Hen has a very smooth, low-carbonated mouthfeel and a subtle, nutty sweetness. Just make sure you buy it in the nitro-can and avoid the easily skunked, clear-glass bottles this beer also comes in.
Cantillon Gueuze
Though I've only sampled this beer once, its sour, acidic flavor will always be seared in my taste memory (in a good way). Located just outside Brussels, Cantillon is one the traditional Belgian producers of lambic beer. This Gueuze (pronounced "gooz") is radically different from normal ales or lagers. There is little hop bitterness but a hugely tart and fruity flavor, thanks to spontaneous fermentation.