A guest post by Marie Davenport (of the forthcoming 3323 Brewery & Distillery in San Francisco, CA).

As a brewer and, um, frequent taster of beer, lambics hold a special place in my cellar. The kumquat-like tartness mixed with the vinegary sourness that hits right in the back of the tongue, slowly coating the mouth before dissipating, the balanced nuance of the wheat and barley, the almost complete lack of discernable hop flavor, the complex and acidic aroma that varies from white wine to hay to sweat, and the delicate combination of “wild” yeasts and bacteria all make me stop what I’m doing and just say “wow.”

Lambic truly embodies its terroir. Taking a sip of Cantillon Kriek Lambic takes me straight to the Senne River Valley, surrounded by cherry orchards, drinking from a jug…   

Like a number of traditional Belgian beers, over the last several decades lambic has been a victim of changing tastes and industrialization. While the traditional version of the style is being revived by a number of brewers scattered across the US and Europe, it will never truly be the same as when it is produced in the Senne Valley. And even there, lambic is changing along with the local geography. 

Lambic is considered to be the “mother of all beers.” Brewing in Brussels began sometime in the 1200s, and the first written documents about lambics date to around 1320, making it the oldest existing beer style in the world. The first lambics, or “yellow beers,” were originally brewed in Lembeek, a village in the Senne Valley where at one point there were 600 inhabitants and 43 breweries. 

By Belgian law, lambic must be made from at least 30% (it is often more like 40%) unmalted wheat with malted barley (the dominant grain in most beers) making up the difference, and at some point in the process the unfermented beer (or wort) must be exposed to airborne yeasts. In this post-Pasteur era, exposing wort to airborne yeasts epitomizes this traditional style. Once all beer was “spontaneously fermented” with airborne yeasts. Now there is only lambic. While all brewing yeasts originated from fruit, the strains (ranging from 80-120) of yeast found in lambic are most likely a result of the breweries’ proximity to the vast cherry orchards that once covered the entire Senne Valley region. These local yeasts and bacteria have been residing in the casks, woodwork, walls, and ceilings of breweries like Cantillon since 1900, so are fully integrated into the infrastructure for now. The brewery cat, an essential part of any good lambic production facility, helps keep the yeasts airborne. Unlike in other beer styles, only aged hops (they’re ready when they start to smell like cheese) are used. The reasons are twofold: 1) the bitterness of fresh hops does not combine well with the natural sourness of a lambic; 2) the antimicrobial powers in fresh hops will kill off too much of the bacteria needed for proper fermentation, but are still potent enough to keep the acetobacter in check, giving a nice balance to a beer that would otherwise turn into malt vinegar.    

If procuring the necessary ingredients doesn’t seem onerous enough, the actual process of making lambic is itself an arduous process. A Dutch law introduced in 1822 (and maintained when Belgium became independent) taxed the size of the mash tun — the vessel where water and grain are mixed to turn the starches into sugars — forcing brewers to save money by creating a very dense and cloudy, or “turbid,” mash. I’ll spare you the details of this type of mashing (if anyone is interested, I will be happy to explain) but will say that extracting starches with this type of mashing is much more labor intensive and time consuming than the English style of using a single infusion. (Think several hours compared to one.) Traditional lambic brewers swear by this turbid mash method and still use it today. After all the sugars are extracted from the grain, the wort is boiled for at least three hours, sometimes all day (a “regular” boil for non-Belgian beers is more like 90 min), and then transferred to a coolship, a shallow vessel in a drafty part of the brewery, where it is allowed to cool overnight and enjoy its first exposure to yeasts and bacteria. When it has cooled sufficiently, the wort is transferred to casks, also home to a variety of yeasts, where it is allowed to age for 6 months to several years. 

Most lambics are blended before drinking, as the aging process greatly affects the taste. A young lambic (6 months — 1 year old), which you will rarely find to drink straight, is considerably sweet and slightly carbonated, and is generally blended into a gueuze (a blend of 1, 2, and 3 year old lambics) or with other older vintages. Older lambics tend to be dry with less carbonation, having cider or wine notes and various levels of sourness. Faro, aged three years, is one of the few lambics available unblended, usually on draft, and is often sweetened with sugar to taste.  

Only a handful of traditional Belgian lambic brewers still exist. The ones with distribution in the US include Cantillon, 3Fonteinen, Girardin, Boon/Oud Beersel, and Timmermans.  Cantillon is of special importance because of the public stance for traditional production methods that brewer Jean-Pierre Van Roy promotes. After he married into the family run brewery in 1978, he set into motion the public argument for traditional lambic brewing by forgoing newer brewing practices, such as trading in wooden vessels for stainless steel and adding syrups or saccharin for sweetening. He also advocates the use of organic and local ingredients when possible. Most of the current large purveyors of sweetened lambic (such as the easy to find Lindemann’s or De Keersmaker lines) still use saccharin and syrups, while Cantillon prefers to use real fruit, letting the yeasts devour the sugars to create a dry beverage.  

Industrialization is not the only change in lambic country. While Cantillon was once able to buy all of the fruit they use in their beers from local farmers, they can now only purchase cherries locally. And the traditional brewing year of October to May now ends in March, at least at Cantillon, where Jean-Pierre cites global warming as the malefactor. 

Traditional lambic is not your run of the mill beer. It embodies time-honored practices and is truly a product of its place. While certain production methods can be replicated, the complex combination of yeasts and bacteria in each bottle cannot. Because of this, no two bottles or vintages are alike. Next time you open a bottle of traditional lambic, take great pleasure in your experience. It will not be repeated.