Oud bruin explained
Oud bruin, or Flanders brown ale, is a beer from East Flanders in Belgium that combines rich malt with a soft sourness from long ageing. Here is how it is made, how it tastes and how to enjoy it.
A brown ale from East Flanders
Oud bruin means "old brown" in Flemish. It is a traditional ale from the province of East Flanders in Belgium, with the town of Oudenaarde often named as its home. The beer is brown, malty and gently sour, with flavours of dark fruit, caramel and sometimes a light tang reminiscent of vinegar or balsamic.
The "old" in the name points to ageing. Oud bruin traditionally spends months maturing, during which bacteria and yeast slowly build its sourness. Strength usually sits between about 4% and 8% ABV.
How the sourness is built
Oud bruin is made with a mixed fermentation. Ordinary ale yeast does the main work, then lactic acid bacteria, mainly Lactobacillus and Pediococcus, slowly produce lactic acid during long ageing. Some breweries also have Brettanomyces in the mix. The result is a rounded sourness rather than a sharp one.
Breweries usually blend young and old beer to set the final balance. Young beer brings sweetness and malt. Old beer brings sourness and depth. Blending lets the brewer hit the same flavour year after year even though each batch ages differently. Our guide to sour beer for beginners covers mixed fermentation in plain terms.
Oud bruin versus Flanders red
Oud bruin is often confused with its neighbour, Flanders red ale from West Flanders. They share a sour, fruity character, but differ in some useful ways:
- Colour: oud bruin is brown, Flanders red is reddish brown.
- Ageing vessel: Flanders red is traditionally aged in large oak vats. Oud bruin is more often aged in tanks without much oak character.
- Acidity: Flanders red usually shows more acetic sharpness. Oud bruin leans malty and softer.
- Sweetness: oud bruin tends to keep more malt sweetness.
Our guide to Flanders red ale covers the western cousin.
What it tastes like
Expect a medium-bodied brown beer with flavours of:
- Raisins, plums, figs and dark cherries.
- Caramel, toffee and a light chocolate note from the malt.
- A soft lactic sourness, sometimes with a hint of sherry.
- Low hop bitterness, kept in the background.
The balance between sweet malt and tart fruit is the point of the style. A good oud bruin is never harshly sour or vinegary. Some versions are blended with cherries or other fruit, which push the fruit flavour forward.
Why age changes the beer
Time is an ingredient in oud bruin. Fresh from primary fermentation, the beer is a sweetish brown ale. Over months of ageing, lactic bacteria slowly turn some remaining sugars into lactic acid. The flavour shifts from sweet towards tart. Some oxidation adds sherry and dried fruit notes. The beer that leaves the brewery is the product of patience, not a quick recipe.
Bottled oud bruin can keep changing. A pasteurised bottle stays fairly stable. An unpasteurised one with live microbes may grow drier and more sour over a year or two. In a hot Indian flat, that change runs faster and less predictably. If you want to keep a bottle, store it upright, away from light, in the coolest place you have. Drink it within the date on the label unless you enjoy experiments.
How to serve it
Serve oud bruin at about 10 to 12 °C in a tulip or a stemmed goblet. Colder than that hides the fruit and malt. A wide glass lets the aromas open as the beer warms.
Pour gently, especially if the bottle has sediment. Leave the last centimetre in the bottle unless you like a slightly yeasty finish. Strength varies, so check the label: a 7% oud bruin should be sipped like wine, not drunk like a session ale.
Food that works with it
Oud bruin's sweet and sour balance makes it a good food beer. Belgians cook with it, notably in a beef and beer stew. Pairings worth trying:
- Slow cooked meats, such as a Bengali kosha mangsho or a Belgian carbonnade.
- Duck or pork with fruit sauces.
- Aged cheeses such as Gouda.
- Chocolate desserts with dark fruit.
The gentle acidity cuts through rich gravies, while the malt sweetness matches caramelised meat. Very fiery curries can clash with the sourness, so go easy on chilli.
How to taste it like a judge
When tasting oud bruin, try to separate three things: malt sweetness, sourness and fruit. Take a sip and notice which arrives first and which lingers. Good examples balance them so no single flavour dominates.
Compare it, if you can, with a Flanders red and an ordinary brown ale. The brown ale shows you the malt base without sourness. The Flanders red shows you sharper acidity and oak. Oud bruin sits between them. Drink small measures with water alongside and do not drive afterwards.
Your first step: find a bottle of oud bruin, serve it at cellar temperature in a tulip and note how its sweetness and sourness change as it warms over twenty minutes.
Common questions
What is oud bruin?
A traditional brown ale from East Flanders in Belgium, malty and gently sour from long ageing with lactic bacteria.
What is the difference between oud bruin and Flanders red?
Flanders red is usually aged in oak and shows more acetic sharpness. Oud bruin is browner, maltier and softer in acidity.
How sour is oud bruin?
Mildly to moderately sour. The sourness balances malt sweetness and should never be harsh or vinegary.
