Faith, Beer, and Other Things That Interest Geoff

Lambic is the oldest existing style of beer in the world. Since at least the 3rd Century B.C. up until the mid-19th Century – when yeast was finally identified and cultivated by scientists – beer was fermented by wild yeasts carried on the open air. This mysterious fermentation by invisible wild yeast is often called “spontaneous fermentation.” For millennia, people who witnessed the regular transformation of steeped grains into a warm, sour, intoxicating drink considered it a form of magic, and in a way, of course, it really is. Surely earlier civilizations must have agreed with Benjamin Franklin, who wrote more recently that beer is proof of the existence of a loving and benevolent God.

At some time in the murky Middle Ages, the beer fermented by wild yeast in an area ranging from Brussels to the nearby Senne Valley countryside became famous around Europe. It was then known as “yellow beer,” and there are lively and colorful images of peasants enjoying the stuff, lovingly poured from earthen jugs, in the works of Breughel the Elder in the 1500’s. Eventually, “yellow beer” became known as “lambic” – a word derived from Spanish, a relic of the long period when Spain ruled over the Netherlands and Flanders. Today, real Belgian lambic is the only beer entirely fermented by wild yeasts that is still brewed commercially.

Traditionally, lambic is aged for one to three years in oak wine barrels. The result is a dry, sour, earthy, and complex drink that hardly resembles beer made with laboratory yeast. Unlike scientifically cultured yeast strains, the wild yeast and other bacteria in lambic (many of which come from the wine barrels during the long fermentation) produce a lot of acids, in addition to alcohol and other flavor compounds that are common in modern beers. Mostly, they produce lactic acid, and lots of it. (Sometimes they produce a lot of acetic acid, or vinegar, but if the vinegary sharpness becomes a bit over-powering, any conscientious lambic brewer will throw that batch of beer out.) Now of course, very few brewers will stand by and allow their yeast strains to produce acidic flavors; they go to great lengths to keep any stray bacteria out of the process. But for millennia the wild yeast and bacteria that naturally found their way into beer had free rein, and all beer was, to varying degrees, sour. The lambic brewers today revel in this sourness, and recognize it for what it is – a continuous, living link to thousands of years of human history.