Written for the Burlington Free Press on June 23rd by Jeff Baker http://www.burlingtonfreepress.com/story/life/food/2016/06/23/lambic-beers-gateway-sours/86290340/
Last week we started an exploration of different sour beer styles. We began with two kettle-soured styles Berliner Weisse and Gose. (One note: I mistakenly indicated that kettle-souring and sour mashing are the same thing. They are closely related, but not exactly the same process.)
This week, we’ll explore live-culture sours, including lambic and Flemish-style sour ales. More than 100 different microbes can be in play in these styles, but the major ones are Saccharomyces, Lactobacillus, Brettanomyces, Pediococcus and Acetobacter. Saccharomyces is a family of yeasts know as “brewer’s yeasts” and Lactobacillus we covered last time (think yogurt’s tangy tartness).
Brettanomyces, or “Brett,” is a slow-moving yeast but a true scavenger when it come to consuming sugar. Brett produces flavors ranging from lemon peel and tropical notes like pineapple to hay and barnyard-y funkiness. It produces small amounts of acid, but is not generally considered a souring culture.
Pediococcus, or “Pedio,” is a bacteria which produces lactic acid, similar to Lactobacillus, but also produces funky, earthy and sometimes downright unpleasant flavors and aromas. When Pedio is kept in check by other yeasts and bacteria, it can play a subtle, supporting role in the beer. Out of control Pedio can lead to off-putting bile-like sour flavors.
Acetobacter is a group of bacteria which, in the presence of oxygen, convert ethanol to acetic acid. Think red wine vinegar.
All of this can sound scary, but the result can be complex, refreshing and quite lovely.
Most peoples’ first introduction to lambics are ones which have been sweetened and have fruit added, such as cherries (Kriek), raspberries (Framboise) or peaches (Pêche). These beers are on the sweet side of life, to be sure, but they start out as fairly sour beers.
lambic is brewed in the Pajottenland region of Belgium, south-west of Brussels in the Senne Valley. The brewing process starts out similar to brewing a standard beer, but after the wort has been boiled, it is run into a wide shallow trough called a “koelschip” (pronounced “cool-ship”). This trough spreads the cooling wort out to maximize surface area. Louvres are then opened to allow the outside ambient air to blow across the surface of the beer. The breeze carries with it native airborne wild yeasts and bacteria, such as the ones mentioned above, which settle on the surface of the unfermented beer.
Now that the wort has been inoculated, it is run into wooden barrels for a series of long, slow fermentations. These barrels are home to yeast and bacteria colonies from previous batches, and once a delicate balance is established over time, lambic brewers do everything they can to not disturb the house “culture.” Fermentation goes in stages as different yeasts and bacteria have different environmental preferences. Some lay dormant until the pH in the beer starts to drop, for instance.
Lambic producers blend their barrels for consistency and to achieve a house style. In terms of flavor, I find that un-fruited lambics, which are pale in color, offer notes of lemon peel, lime juice, hay and flowers. Almost like drinking a glass of lemon-lime-ade in a summer field.
It can be too sour or too funky for some drinkers, though. Fruit and sweeteners are added to this base beer to make it more approachable to the average palate. (It should be noted that not all fruited lambics are sweetened. Many serious fruited lambics retain their sourness.)
Most lambic houses will release a “Gueuze” (also spelled Geuze, but not to be confused with Germany’s Gose). This is typically a blend of 1-, 2- and 3-year-old un-fruited lambics. Old beer adds complexity and acidity, while young beer adds vibrance.
For Gueuze, look for the approachable Lindemans “Cuvée René,” the limited edition Boon “Black Label” and the sometimes hard-to-find but always stunning Cantillon “Gueuze 100% Lambic.” All of these producers also offer very fine fruited lambics. Most of the Lindemans fruited bottlings are also sweetened, making them great gateway beers. There is a Kriek version available of Cuvée René which is un-sweetened and Cantillon makes some truly incredible sour fruited lambics, but they’re often scarce in Vermont.
In the Flemish region of Belgium, another unique style of sour beer was developed: Flemish sour red-brown ales. These beers start off as malty red or brown ales but instead of being inoculated in a koelschip, the wort goes directly into very large wooden barrels called foudres (also spelled foeders). These barrels are home to an established ecosystem of the various microflora discussed above, with the addition of yeasts and bacteria that are native to the Flanders region.
Although Flemish sours go through a similar series of slow fermentations the end result is rather different than lambic. These sour red and brown ales offer more vinous characteristics and a sharp acetic bite. Flavors of sour cherries, tart Pinot Noir, leather, lemon rind and currants are common. Younger batches will have more residual sweetness and are often blended with older batches for balance and consistency.
The benchmark for the style is the house of Rodenbach. Try their eponymous younger bottling for the sweet-tart entry level, or reach for their “Vintage” or “Grand Cru” offerings for more sour examples. Other great examples are Omer Vander Ghinste “Cuvée des Jacobins Rouge” and Verhaeghe “Duchesse de Bourgogne.”
Just like lambic producers, some Flemish producers add fruit. Look for Omer Vander Ghinste “Kriek des Jacobins” and the hotly anticipated Rodenbach “Alexander,” both of which have sour cherries added.
Have you found a favorite sour beer? Tell me about it on Twitter @aPhilosophyOf.
Jeff S. Baker II is the Curator of the Curriculum for Farrell Distributing.