These beers are primarily associated with the waterside city of Oudenaarde. They are brewed from a blend of malts, including the reddish Vienna malt (similar to English crystal malt), with a little roasted barley to add the brown color. Traditionally they are mashed by simmering overnight rather than for a couple of hours as most other brewers do it, and then boiled in the copper for twelve hours.
Fermentation in open vats for up to six weeks is followed by storage in old oak casks to mature for nine months before bottling, where they will condition further.
The best-known of these brown ales come from the Liefmans brewery (which dates from 1679), particularly the fully-matured version, Gouldenbrand (6%). You can recognize Liefmans beers by their distinctive tissue-wrapped bottles. Unfortunately, since being taken over by the Riva group in the early 1990s, production methods have changed, and the beer is no longer mashed or boiled in Oudenaarde.
There are only a few other decent examples of this rare style: Clarysse Felix Oudenaards Oud Bruin (5.5%) is delightfully fruity, sweet and sourish. Don’t gulp it, sip it and savor its rich mixture of flavors.
Another excellent Oud Bruin is only found in a small town north of Oudenaarde called Eine. The brewery is called Cnudde, and the beer is only available on draught in the town.