Unlike conventional ales and lagers, which are fermented by carefully cultivated strains of brewer's yeasts, Lambic beer is instead produced by spontaneous fermentation: it is exposed to the wild yeasts and bacteria that are said to be native to the Senne valley, in which Brussels lies. It is this unusual process which gives the beer its distinctive flavour: dry, vinous, and cidery, with a slightly sour aftertaste.
Today the beer is generally brewed from a grist containing approximately 70% barley malt and 30% unmalted wheat. When the wort has cooled, it is left exposed to the open air so that fermentation may occur spontaneously. While this exposure is a critical feature of the style, many of the key yeasts and bacteria are now understood to reside within the brewery and its (usually timber) fermenting vessels in numbers far greater than any delivered by the breeze. Up to 86 microorganisms have been identified in Lambic beer, the most significant ones being Brettanomyces bruxellensis and Brettanomyces lambicus. The process is generally only possible between October and May as in the summer months there are too many unfavourable organisms in the air that could spoil the beer.
Since at least the 11th century and probably earlier, hops have been used in beer for their natural preservative qualities as well as for the pleasant bitterness, flavour, and aroma they impart. Today they still provide bitterness, flavor, and aroma in almost all beer styles except Lambic. Since the method of inoculation and long fermentation time of Lambic beers increases the risk of spoilage, Lambic brewers still use large amounts of hops for their antibacterial properties. In order to avoid making the beer extremely bitter, however, aged, dry hops (which have lost much of their bitterness) are used. Consequently, Lambics often have a strong, cheese-like, "old hop" aroma, in contrast to the resiny, herbal, earthy hop bitterness found in other styles.
After the fermentation process starts, the lambic is siphoned into old oak or chestnut barrels from the Porto region of Portugal or the Jerez region of Spain. Some of the brewers prefer used wine barrels. The lambic is left to ferment and mature for one to two or even three years. It forms a "velo de flor" of yeast that gives some protection from oxidation, in a similar way to vin jaune and sherry; the barrels are not topped up.
Another important feature of Lambic is that it is usually a blend of at least two different beers; many 'producers' are in fact blenders who buy beers from other brewers, and blend two or more together to create the desired result. A good gueuze, for example, may have occupied space in several different cellars over 6 years or more. Despite this complex production, the locals are justifiably proud of their unique beer, and recent years has seen an explosion of interest around the world for this unusual beverage. Whilst those outside of the area are most likely to find the bottled gueuze and fruit versions, there are a wide variety of styles available to the local drinker, and they are often blended again or sweetened with sugar or flavoured syrups before drinking, as some examples can be extremely tart.
Lambic beer is widely consumed in Brussels and environs, and frequently features as an ingredient in Belgian cuisine.
Where to Worship the Lambic Nectar Carlton Reid Makes a Pilgrimage to Brussels to Sample the Local Beers and Pay Homage to the Breweries
Mar 08, 1998; YOU would think a city that prided itself on a statue of a little boy peeing would be well served with WCs. Far from it. Brussels...