Oud Bruin (“old brown”), also known as Flanders Brown, is a style of beer originating from the Flemish region of Belgium. The Dutch name refers to the long aging process, up to a year. It undergoes a secondary fermentation, which takes several weeks to a month, and is followed by bottle aging for several more months. The extended aging allows residual yeast and bacteria to develop a sour flavor characteristic for this style. While some examples of an Oud Bruin may be aged in oak, typical beers in this style are not, and this is what helps Flanders Brown ales distinguish themselves from the more sour Flanders Red ales.
This style of beer is medium bodied, reddish-brown, and has a gentle malty flavor and no hop bitterness. The aroma is a complex mixture of fruits and estery smells of plum, raisin and cherry. The flavor is sweet, caramel, fruity, tart, and slightly acidic, caused by various bacteria in the maturation process. In a good example, the tartness is often balanced with a malty character, tasting of toffee and a giving a “sweet-and-sour” impression. Commercial versions may mix aged beer with younger, sweeter beer to temper the acidity and create a more complex flavor. (Article from Wikipedia: “Oud Bruin”)
Oud Bruin Characteristics
AROMA / BOUQUET:
Complex combination of fruity esters and rich malt character. Esters commonly reminiscent of raisins, plums, figs, dates, black cherries or prunes. A malt character of caramel, toffee, orange, treacle or chocolate is also common. Spicy phenols can be present in low amounts for complexity. A sherry-like character may be present and generally denotes an aged example. A low sour aroma may be present, and can modestly increase with age but should not grow to a noticeable acetic/vinegary character. Hop aroma absent. Diacetyl is perceived only in very minor quantities, if at all, as a complementary aroma.
Dark reddish-brown to brown in color. Good clarity. Average to good head retention. Ivory to light tan head color.
FLAVOR / TASTE:
Malty with fruity complexity and some caramelization character. Fruitiness commonly includes dark fruits such as raisins, plums, figs, dates, black cherries or prunes. A malt character of caramel, toffee, orange, treacle or chocolate is also common. Spicy phenols can be present in low amounts for complexity. A slight sourness often becomes more pronounced in well-aged examples, along with some sherry-like character, producing a “sweet-and-sour” profile. The sourness should not grow to a notable acetic/vinegary character. Hop flavor absent. Restrained hop bitterness. Low oxidation is appropriate as a point of complexity. Diacetyl is perceived only in very minor quantities, if at all, as a complementary flavor.
MOUTHFEEL / PALATE:
Medium to medium-full body. Low to moderate carbonation. No astringency with a sweet and tart finish.
A malty, fruity, aged, somewhat sour Belgian-style brown ale.
Oud Bruin beer characteristic descriptives from 2008 BJCP (Beer Judge Certification Program) style guidelines. (http://www.bjcp.org)