The Magic of Lambic
The notion of brewing a “one-off” is not uncommon. But there is a whole family of styles, the lambics, that fit said bill with respect to convention. So individual are they, that virtually every aspect of their production is anarchistic. Brewing, fermentation, aging, maturation, and even ingredients are distinctive. The result is a beer that presents an unmatched sensory tapestry. That is saying something, considering that these beers originate in Flemish Belgium.
Land of Lambic
To say that lambics are brewed non-traditionally would be erroneous. It is quite the opposite, as no other beers are as ensconced in tradition. Unusual or extraordinary are adjectives that better befit the style. Lambics exhibit so many different personalities that they may be hard to embrace, but to the lambic smitten, they are beloved.
The historical and current stronghold of lambic is the city of Brussels, Belgium, and the area immediately to its west and south, Payottenland, where the landscape quickly becomes rural. To the south along the River Zenne is a small town named Lembeek, just one of several local villages or words that may be responsible for the beer’s moniker. Today’s lambics are little different, if at all, from their ancestors of 400 years ago. No other beer style can lay such bold claim. A look at the lambic method divulges its agrarian and anachronistic charm.
Bushels, Bugs and Barrels
Indigenous beers are, of course, made from locally available raw materials. In Payottenland, that would be a brew based on barley, but also a fair amount of wheat. Raw wheat is preferred over malted. Anywhere from 30 to 40 percent is used, with 30 percent being the decreed lower limit for the style. Malted barley offers a surfeit of the magical enzymes needed to convert the starches in the wheat. Due to the floury nature of the raw wheat in the grist, the lambic mash is turbid. This necessitates a method to break down the proteins and starches. The milky liquid is drawn off, boiled, and returned to the mashtun to raise the whole to an enzyme-friendly temperature. Mashing then continues in a more familiar way.
Even the simple act of boiling lambic wort is novel. It is boiled for 3 to 6 hours, at least twice that of other beers. This aids in breaking down the wort components. There is yet another deviation in the hopping of a lambic. Hops that have been aged for a couple or more years are added in staggering quantities. Over the aging period, the labile nature of hops causes them to lose almost all of the properties that make them desirable in most beers (bitterness, flavor and aroma), but retain those characteristics important to all beers (preservative and antioxidant). Little or no hop character is detected in a lambic. The wort has a gravity of between 12 and 14 degrees Plato, so, only in that respect, is it rather modest. This will produce a beer with 4.5 to 5.5 percent alcohol by volume (ABV).
The schematic gets especially divergent at this point. Lambic fermentation is the most interesting and significant step in the production, and the single most important contributor to the profile. The wort is cooled, not by induced chilling, but by the implementation of “cool ships.” These are large, shallow vessels in the attic of the brewery that are open to the environment. The wort is pumped to the cool ships, where it eventually equilibrates to match the ambient temperature. The configuration allows more surface area for heat dissipation and exposes more of the wort to the resident microflora.
While every other brewer on the planet would consider this practice tantamount to beericide, lambic brewers welcome the invaders. The microorganisms may come from hiding places within the brewery’s attic, or from the surrounding landscape via opened windows or louvers. As the native “bugs” are critical to the character of the beer, things are left pretty much undisturbed within the walls, lest the wonderful effect of nature be made imbalanced. Centuries of spontaneous fermentation have rendered the microfloral ecosystem so stable that the wort:organism symbiosis is incredibly consistent, with inevitable minute variations manifested in the brew. No two beers are alike. Both wild yeast and bacteria compose the amalgam. The most important macrobiota are spiders, which stand sentry against intruding flies.
When cool, the wort is transferred to wooden casks, which come from various wineries and house another sub-population of organisms within their pores. The variety of influential organisms is mind-boggling, sometimes numbering over 100! If this seems like haphazard brewing, it is not. Lambics are not made in the warm months because an abundance of unwanted bugs abounds at this time of year. Crazy as it may seem, they would spoil the beer.
An Acquired Taste
The initial fermentation in the barrel is allowed unfettered, such that the foam spews forth from the bunghole. After the primary fermentation has abated, the hole is sealed with a porous cloth that acts as a functional barrier. It is at this stage, which may last months, that a lambic undergoes its enchanting metamorphosis as the myriad organisms metabolize the wort. Yeast labors in the usual fashion, and the bacteria metabolize other components into a complex mosaic of flavors that are most often associated with wine. Two such bacteria, Brettanomyces bruxellensis and lambicus, are named for the city of Brussels and lambic beer, respectively. Some Brettanomyces strains even work on the residual unmalted wheat.
To say that the beer that arises from this mystical, yet controlled fermentation is complex would be a gross understatement. Lambics are an acquired taste. What initially may seem like a crass assault on the palate becomes a mélange of discernable flavors and aromas to a perceptive beer drinker. Lactobacillus strains produce a cidery and sour character. Brettanomyces strains contribute the musty, horse blanket, and earthy notes. Hints of fruit, vinegar and cheese are perceptible, too. All of this character with a minimal wisp of hops. Even the barrels contribute some woody and winey notes. Lambics are as dry as any beer. The color is gold to amber. Often they gain color and complexity with age, and they can age for a few years.
As recently as 1900, there were as many as 300 lambic breweries around Brussels; today there is a dozen. Straight lambic is most often served from a cask with virtually no carbonation. Some lambics are bottled. Cantillon makes a straight lambic, but most are blended from different vintages, an artisanal endeavor it its own right. In fact, blending is really what lambic is all about. The various blends give rise to different styles of lambic known as gueuze, fruit lambic, and faro, as well as simple “blended lambic.”
Gueuze—the most widely available member of the lambic family—is at first study simply a blend of old and young lambics. Gueuze differs from straight lambic in that it presents itself with a good measure of carbonation. The young lambic contains a bit of unfermented sugar, which is subsequently used to produce the carbonation in the bottle. The ratio is left up to the blender; anywhere from two to seven lambics are blended, and the corked bottles are laid down for a period of time to carbonate. One then gets all of the complexity of a lambic, with the pleasant effervescence of champagne.
Fruit beers can be gimmicky, but not lambic versions. The most common fruit lambics are kriek (cherry), pêche (peach), and framboise (red raspberry), but macerated black cassis (black currant) and Muscat (grapes) also find their way into the maturing beer, kick-starting the fermentation. The amount of fruit added to the beer is quite liberal, on the order of 1 kg per 5 liters. The marriage is harmonious, the honeymoon lengthy and lusty, being anywhere from a few weeks to several months. The fruit is also a vehicle for more wild yeast, which further paints the palette of the beer. The preferred cherries are the sour Schaarbeek variety, though others are used extensively. The pit adds a touch of almond essence to the character.
Young, blended lambic sweetened with dark candi sugar is known as faro. The extra sugar requires that the blender pasteurize the brew to arrest fermentation and retain the sweetness. Though uncommon, several are still produced in Brussels and Payottenland, the most available being Faro Pertotale from Brouwerij Frank Boon.
To get an authentic dose of lambic culture, one need only to travel to Brussels and just another 10 miles beyond. Of the area’s dozen or so lambic venues, most are actual breweries, but a couple are just blenders who purchase lambic and ply their craft. They are mere miles apart. The numerous cafes in the area serve up the area’s offerings, too, with Le Bier Circus in Brussels a favorite of lambic seekers. The Cantillon Brewery is home to the Gueuze Museum, as well as being a world-class brewery. Other notables in the domain are Brouwerij Frank Boon, Belle-Vue, Drie Fonteinen, Girardin, Hanssens, Lindemans and Timmermans, among others.
Many of these breweries export their exquisite products. In the United States, the French Broad River Brewery in Asheville, NC, makes a well-aged and perfect example of a blended lambic. New Glarus Brewing in southern Wisconsin makes Raspberry Tart, spontaneously fermented in oak barrels, that is heaven in a glass.
Cantillon Broucsella 1900 Grand CruABV: 5.0
Tasting Notes: Named after the year 1900, when the Cantillon family moved from Lembeek to Brussels. The only available unblended lambic. Pours flat, with a musty and sour aroma. Dark gold to light amber. The flavor is quite assertive with woody, phenolic, vinegary, and even fungal notes. One-third unmalted wheat, two-thirds malted barley, aged for three years. Not for the timid. A classic in every respect.
Cantillon Gueuze (2002)ABV: 5
Tasting Notes: Dark gold, slightly hazy, with a massive head. The lace clings tenaciously to the emptying glass. Lactic and vinegar hints in the aroma, along with a little lemon. The earthy notes are a bit subdued. Reasonably mellow to a wizened lambic palate. A blend of one-, two-, and three-year-old lambics. Seductive and appetizing.
Drie Fonteinen Oude GeuzeABV: 6.5
Tasting Notes: Pours rambunctiously, golden, and a little turbid. Citrusy and lactic aroma, with a musty, almost cheesy nose. The delicate lace adheres to the glass nicely. Blended from three different procured lambics, all aged on site. Legendary for its aging qualities. Earthy and effervescent.
K. Florian Klemp
K. Florian Klemp is a research analyst at Duke University in Durham, NC, and an award-winning homebrewer.