Go Sour

Move over, pumpkin beer – Flemish sours are the perfect beer for fall


I’m tired of all these pumpkin beers and their silly names. When did it become a requirement to brew liquid pumpkin pie two months before fall even starts? Sure, the first few you drink when they hit the stores way too early in September are great and heighten your anticipation of the upcoming autumn, but there’s only so much pumpkin and allspice a person can take. Although I could easily rant about pumpkin beer for hours, I won’t waste your time. Instead, I’d like to be constructive and suggest an alternative.

For me, there’s no beer that’s better suited to a cold autumn evening than the deeply complex, acidic, sour ales from the northern half of Belgium called Flanders. With rich sour cherry and tart green apple flavors that perfectly contrast with sweet caramel and vanilla notes, the sweet-and-sour flavor profile of these ales is chock full of distinctively autumnal tastes. Caramel apples, cherry pie, rustic red wine; they can all be found in the deep garnet of a Flemish sour. These ales are much more than a fall weather treat, though. Thanks to a transformative brewing process, these time-intensive brews showcase the highest levels of complexity and craftsmanship that the beer world has to offer.

Flemish ales are generally broken up into two categories: Flemish Reds and Flanders Oud Bruin. Style guidelines will tell you that Flemish reds are aged in oak vats and Oud Bruins are aged in metal vats. These days, the line between the styles has blurred – oak aging now dominates both reds and bruins. Because of this, the most important difference is the malt composition of the base beers. Flemish reds start out pale, sweet, and mildly malty. Oud Bruins (which translates to “Old Brown”) start darker, with a deeper, more roasted malt character. The base beers are, frankly, quite boring. It’s the aging process that makes them truly special.

A diagram at Rodenbach Brewery shows the aging and blending process.

Traditionally, Flemish sours are blended beers. This means that similar base beers of various ages are blended together until a desirable flavor profile is obtained. The ages of the blending components can be anywhere from a relatively young 2 months to upwards of 4 years, an incredible amount of time for beer. During those long months, the beer isn’t alone. Thanks to a multitude of microorganisms eating their way through its sugars and alcohol, the beer is constantly evolving and developing new flavors and aromas. The bacteria Lactobacillus and Pediococcus produce lactic acid, which provides a sharp tartness. Acetobactor provides acidity in the form of acetic acid, and the esters and phenols produced by the wild yeast Brettanomyces bring some farm-animal funk. This microflora is what truly shapes the flavors and aromas of these beers, transforming them from middling malty ales to beers with layers upon layers of complexity.

That being said, brewers can’t simply rely on the bacteria to do all the work while they sit back and relax. It takes a masterful hand to craft a Flemish sour, and it doesn’t take much to screw it up. The traditional Belgian brewers have a clear upper hand, and it shows in the results. Many attempts from new craft brewers struggle with the particular aspects of Flemish sours that truly take experience to achieve: balance and complexity. In the classic Flemish sours from names like Rodenbach, Bockor, and Liefman’s, all of the contrasting and complementary flavors and aromas are in perfect harmony with each other. With just one of many variables out of sync, a Flemish sour can fall flat. This isn’t to say that there aren’t any excellent modern examples of Flemish sours, (I’ve recommended a few below), they just all happen to come from current masters of the brewing scene with plenty of experience under their belts.

At the end of all of these years of brewing, aging, trial, and error, the end result is a deeply flavorful, endlessly complex ale dynamically suited to contemplative sipping or as an accompaniment to a festive meal. Try a Flemish red instead of the usual red wine at the holiday dinner table and a big Oud Bruin with dessert. While pumpkins and spice certainly dominate the popular fall palate, it’s hard not to associate the flavor profiles of these Flemish ales with autumn. More than that, these are beers in which you can truly taste craftsmanship, time, and nature, not just last year’s pumpkin puree and a bit of cinnamon. Let’s face it, you’re going to get sick of pumpkin this year (just like you did last year), so when you do, ditch the gourd for a Flemish sour. By the end of pumpkin beer season, you probably won’t miss it at all

Flemish Sours, Old and New

Here are my recommendations for Flemish sours. I’ve listed the classics that you should start with and the modern masterworks you should hunt down once you’re obsessed with the style.

Classics from Flanders

The few remaining classic Flemish sour producers have a bit of an advantage. Not only can these breweries trace their recipes and brewing heritage back hundreds of years, many can trace their equipment, yeast, and bacteria cultures back just as far. These examples are true benchmarks of their style.

Grand Cru, Brouwerij Rodenbach
Roeselare, Belgium. 6% alcohol by volume, $10 for a 750-milliliter bottle
The flag-bearers of the Flemish red style, Rodenbach can trace several of the oak foeders (huge wooden vats) it currently uses to mature its beers back to the 1830s. 66 percent of this beer spends two years in those foeders, while the other 33 percent is younger. There’s an endless array of tart fruits on the palate: cranberry, cherry, raspberry, and lime all backed up by a syrupy caramel sweetness.

Cuvee des Jacobins Rouge, Brouwerij Bockor
Bellegem, Belgium. 5.5% ABV, $6 for an 11.2-ounce bottle
In 1892, Brouwerij Bockor first began to produce its flagship Oud Bruin called Bellegem’s Bruin. These days, it’s better known for this Flemish red style ale. Fermentation is started by airborne yeast in a large shallow pan called a coolship and finished in oak foeders from France’s Cognac region for at least 18 months. This is one of the most complex beers in the world, with dozens of distinguishable flavors on top of the traditional dark cherry, sweet vanilla and rich caramel notes.

Goudenband, Brouwerij Liefman’s
Oudenaarde, Belgium. 8% ABV, $12 for a 750-milliliter bottle
Liefman’s started making Oud Bruin way back in 1679. Ownership and brewing processes have changed many times since then, but Goudenband is still considered one of the defining beers of the Flanders Oud Bruin style. It’s currently brewed by Duvel-Moortgat, then shipped back to one of Liefman’s original breweries for fermentation and several months of aging in stainless steel tanks. Goudenband is deeply malty, with plenty of rich toffee and dried fruit flavors balanced by a good dose of fresh green apple tartness.

Modern Masters

Most of the new-world takes on this style miss the mark on balance and complexity, over-emphasizing one of the many intertwined characteristics of a Flemish sour. A select few masters of the modern craft beer scene, however, have made excellent Flemish sours with their own unique twists. These won’t be the easiest (or cheapest) beers to get your hands on, but they’re worth the hunt.

Red Poppy, Lost Abbey
San Marcos, CA. 5% ABV, $16 for a 375-milliliter bottle
Lost Abbey is helmed by 17-year industry vet Tomme Arthur, one of the pioneers of Belgian and experimental brewing in America. Red Poppy is a modern take on a classic Flemish red aged for a relatively short six months in oak. It compensates for the aging length by adding a very healthy dose of sour cherries to the barrel. The result is a bracingly sour yet balanced ale that’s chock full of intense cherry flavor, spicy oak, and sweet caramel.

Supplication, Russian River Brewing Company
Santa Rosa, CA. 7.8% ABV, $14 for a 375-milliliter bottle
Vinnie Cilurzo, head brewer at Russian River, opened his first brewery 19 years ago, and has since transformed the craft-brewing world through his experimentation with wine-barrel aging and sour beer styles. Supplication starts out as a brown ale, then ages in Sonoma County pinot noir barrels for 12 months with sour cherries and a handful of bacteria and yeasts. Incredibly complex in aroma, this ale packs a fruit stand’s worth of berries into the glass expertly balanced by rich, dried fruits and toffee flavors.

Prolegomena, Hill Farmstead Brewery
Greensboro Bend, VT. 8.5% ABV, $15 for a 375-milliliter bottle
Before opening Hill Farmstead, Shaun Hill honed his skills at local Vermont staples The Shed Brewery and Trout River Brewing Company and abroad at Denmark’s Nørrebro Bryghus. His small farmhouse brewery in Vermont’s Northeast Kingdom produces some of the most highly regarded American and Belgian ales in the world. Prolegomena is his take on a Flemish sour, blended from beers aged in both wine and port barrels. Savory tobacco, intense caramel, and bright green apple flavors are all wrapped up in an excellently creamy mouthfeel.

Photos by Milo Profi courtesty of Visit Flanders via Flickr (Creative Commons), and Dan Noon via Flickr (Creative Commons)

Frank is a Biomedical Engineering major at Drexel University with a serious interest in the world of craft beer. When he’s not studying how to engineer solutions to human disease and injury, he can be found visiting breweries and bottle shops expanding his knowledge of brewing techniques, beer styles, and history.


  1. dr says:

    Duchesse de Bourgogne reigns supreme among the Flemish sours.

  2. sesodtae says:

    let’s also give credit to the Will Meyers, co-brewer of Prolegomena.

    • Good call, with 20 years at CBC he fits right in with this crowd.

Leave a Reply