Belgium probably has given the world more unique and complex styles of beer than any other country on the planet. Sure you can make arguments for England and Germany, but the intensity and diversity of flavors found in Belgian ales is unquestionably impressive.

It is from the Flanders region of Belgium that some of the world's most unique beers originate. Flanders red ales or Flemish sour ales and Oud Bruin (Old Brown) share the tartness of the more well-known lambic style of ales, but lack some of the funky barnyard aspects found in true lambic.

Like lambic, the tart notes in Flanders red and Oud Bruins come from extended aging in oak barrels. Aging works to increase the acetic acid character of the beer. Acetic acid gives vinegar its distinct flavor and aroma, and hints of balsamic vinegar in sour ale are intended. Many of these beers also are purposely exposed to the lactobacillius bacterium, which further increases the tartness of the beer as well as its complexity.

Another thing sour ales share with lambic is blending. Once the aging process, which can be a year or more, is complete, the beer is blended with a newer batch to balance and round the beer. In Belgium, blenders are considered to be every bit the experts that brewers are here.

The finished product will appear a deep red to dark brown, and the aroma will feature cherries, plum and citrus, and of course the sourness will be readily detectable. The flavors are in line with the aroma, with notes of black cherry, plum, orange and sour.

These beers are oddly thirst quenching and refreshing, which comes as no surprise to anyone who has had a light salad with balsamic vinaigrette dressing on a hot day. The tartness slakes the thirst and refreshes the palate.

Flemish sour ales are considered the most wine-like of beers because of their complexity and color, but they have a uniqueness that isn't easily likened to any other beverage.

Liefman's Goudenband is probably the most well known Oud Bruin. It features tart fruit and malt notes and a fairly lively, almost biting, carbonation. Another fine example is Verhaege Vichtenaar, which has a much more oaky aroma and flavor. Petrus Aged Pale and Petrus Oud Bruin can also be found in the United States.

Verhaege Duchesse De Bourgone and Rodenbach Classic are the most widely available of the sour red ales. Rodenbach also makes a Grand Cru version and a fruit version called Rodenbach Redbach, with 25 percent cherry essence added to 75 percent Rodenbach Classic. While Redbach is maligned as not authentic by many beer snobs, it does maintain the classic tartness of sour ale, though there is no mistaking the sweet influence of the cherries.

Also available in the U.S. is an Italian version of the style that has earned rave reviews from fans of the sour ale style. Panil Barrique brewed in Torrechiara-Parma, Italy, captures the essence of the Belgian style wonderfully, but is less sweet and mustier, like a lambic. Aged in cognac barrels rather than plain oak, Panil Barrique (a barrique is a 60 gallon wooden barrel designed to maximum wines exposure to wood for more complex styles) features flavors not found in traditional Flemish sour ales.

For an American approach, seek out New Belgium La Folie around the Denver area. The makers of Fat Tire have remarkably captured the essence of Belgium's sour ales.