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]
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]
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 and aging processes resulting in different taste characteristics.