The 12-litre bottle of Vieille Bon Secours ale has been stored for the last 10 years and has an alcoholic volume of 8 per cent.
The beer has been described as having a complex taste with citric, caramel and toffee flavours with an undertone of liquorice and aniseed.
Only a few other bars and restaurants are believed to stock the beer, which can also be bought online and is available in blond, amber and dark.
Belgian Beer Ambassador and Master Beer Sommelier Mark Stroobandt, said: “All three varieties are complex in flavour but are well balanced so the alcohol is not intrusive.
“Each have a unique and refreshing citric tart flavours intermingled with apricot-like and malty fruitiness to caramel-toffee flavours counterbalanced with a distinct hoppy-bitterness with a spicy undertone of liquorice and aniseed.
“It’s a very special drink for very special occasions.”
Muir Picken, executive chef of the Belgo Restaurant, who currently has one bottle of the beer left in his cellar, said: “At 12 litres it is pretty heavy duty – it takes two people just to pour it.
“A large part of the cost is the bottle itself but it is a very rare niche beer.”
The ale is a brewed by Belgian firm Caulier since 1995 and is originates from the country’s Walloon region.
The restaurant have sold three bottles of the extravagant beer but a single bottle has stood unopened in the cellar for over a decade.
Now Muir faces the dilemma of giving the bottle away or waiting to sell it.
He added: “We have sold three bottles in the past – but we have had one unopened in the cellar for quite some time and I’m not sure what to do with it.
“I would rather give it to our loyal customers than some city boys who sometimes walk in and say give me the most expensive beer that you have.
“I don’t know whether to sell it or give it away to some of our locals and let some beer connoisseurs try it as well.”
The next most expensive beer is Samuel Adam’s Utopia which is brewed by the Boston Beer Company, USA, and sells for £60 a bottle.