Oud Bruin
Liefman's oud bruin
Country of origin	Belgium
Yeast type	Top-fermenting
Alcohol by volume	4 - 8%
Color (SRM)	15 - 22
Bitterness (IBU)	15 - 25
Original gravity	1.043 - 1.077
Final gravity	1.012 - 1.016
Malt percentage	90% - 100%

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.^[1] Usually, cultured yeast and bacteria are used, as stainless steel equipment does not harbor wild organisms as wood does.^[2]

History

These beers were kept as so called provision beers, to be stored and allow the flavour to develop. Liefmans Brewery has been brewing the style since the 17th century.^[2] Historical examples tended to be more sour than modern commercial products. Brouwerij De Brabandere in Bavikhove still produces a traditionally barrel-aged oud bruin under the Petrus brand.^[3]

Characteristics

This style of beer is medium bodied, reddish-brown, and has a gentle malty flavor and no hop bitterness. Commercial versions may mix aged beer with younger, sweeter beer to temper the acidity and allow for further fermentation.^[4]

Because of the reddish-brown colour, the Flanders red ale could be confused with Flanders browns, but the differences include different brewing techniques & aging processes resulting in different taste characteristics.

Examples

• 't Verzet Oud Bruin (Anzegem, Belgium)
• Ichtegem Oud Bruin (Ichtegem, Belgium)
• Liefmans Goudenband (Oudenaarde, Belgium)
• Petrus Oud Bruin (Bavikhove, Belgium)
• Queue de charreu brune (Comines-Warneton, Belgium)