Brewers are sticklers for cleanliness.

That’s because spick-and-span equipment and proper brewing protocol allow yeast strains to perform a military-precise fermentation march toward a desired flavor profile. But if wayward bacteria or fungi enter the mix, flavors and aromas can scatter in tart, funky directions: the symptoms of infection and a reason to send beer swirling down the drain.

Yet one brewer’s accidental infection is another brewer’s long-standing tradition. For around 500 years, the signature sip of Brussels, Belgium, and the mainly rural Senne Valley to the west, has been the winelike lambic, a spontaneously fermented ale that’s as complex and sour as it is appealing. This rustic beer was born on the region’s farms and brewed with their agricultural bounty: a grain bill of at least 30 percent unmalted wheat and the remainder barley malt.

At first lambics follow the standard brewing procedure: grains are boiled to create wort (the sugar-rich broth that becomes beer). But then things take a left turn. Instead of adding the typical fresh hops, lambic brewers rely on aged, stale hops that have lost their bitterness and aromas but retain their preservative prowess. The oddness continues with the next step, as the steaming wort is pumped to large, shallow trays called “coolships,” where the liquid cools overnight. Windows are flung open. Catching a ride on air currents, microscopic yeasts and bacteria settle into the broth. The wild microcritters help jump-start fermentation before the inoculated wort is transferred to wooden barrels, which teem with colonies of bacterial buggers famished for a sugary buffet.

Next, brewers twiddle their thumbs. Lambics take their sweet time to finish fermenting and create their intricate, acidic profile. Most lambics are not served straight, an experience somewhat like slurping vinegar. Instead, lambics are fermented with fruits such as cherries, raspberries, black currants, or peaches, which sweetly temper acidity. Alternately, batches of one-, two-, and three-year-old lambics are blended, bottled, and allowed to continue aging and fermenting. Called gueuze, the result is a dry, somewhat fruity elixir with a lip-scrunching sourness.

Like Champagne in France, a true lambic can only be produced in this Belgian region. And precious few traditional lambic breweries remain. The most revered is Brasserie Cantillon, which has made the tart stuff since 1900, while Brouwerij Boon, Lindemans, and 3 Fonteinen also craft exceptional lambics; Oud Beersel and Gueuzerie Tilquin source wort from elsewhere and ferment it at their facilities. Additionally, some breweries such as Hanssens Artisanaal source an assortment of aged lambics, then blend them into finished products.

Given their forceful flavors, lambics are best matched to equally assertive cheese. Go for a pungent and crumbly Gorgonzola, such as DCI Cheese Company’s small-batch Salemville Amish Gorgonzola or the Amablu Gorgonzola from the Caves of Faribault. Also great is a tangy goat cheese such as Chevita from Tumalo Farms. Alternatively, a sweet and fruity lambic, such as the cherry-crammed Lindemans Kriek or black currant–driven Cassis, will find its match in a rich and creamy mascarpone from the likes of Wisconsin’s BelGioioso or Crave Brothers Farmstead Cheese. With lambics and cheese, sourness has never tasted so sweet.

Recommended Lambics

Brouwerij Lindemans
Lindemans Cassis
Of all of Lindemans’ superb fruited lambics, I favor Cassis. Black currants create a violet-red color and a sweet, mixedberry nose, which is echoed in the flavor. But the lactic tartness does a bang-up job balancing sweetness.





Brasserie Cantillon
Rosé de Gambrinus
The framboise is fermented in oak casks with fresh raspberries, resulting in a dry, tart tango of fruit and funk. Young, the berries dominate; wait a few years, and the wild yeasts will gobble the raspberry goodness.

Oud Beersel
Oude Geuze Vieille
The Belgian producer’s rustic gold gueuze combines breakneck carbonation with a grassy, leathery scent, loads of lemon flavor, and a tingly acidity that’s like an alarm clock for your taste buds.





Brouwerij Boon
Oude Geuze Mariage Parfait
Mainly made with lambic that’s at least three years old, the straw-gold, Champagne-bubbly brew packs an oaky aroma bathed in barnyard funk. The bitterness is balanced by acidic fruit and, thanks to the wood, a touch of vanilla.

Gueuzerie Tilquin
Oude Gueuze Tilquin `a l’Ancienne
Run by Belgium’s Pierre Tilquin, the one-man operation’s winning releases include this gorgeous unfiltered gueuze made with wort from the likes of Boon, Lindemans, and Cantillon. The fermented result: hazy gold, with notes of lemon-drenched green apples.






Written by Joshua M. Bernstein