A very limited selection of the Quadrupel production is barrel-aged each year in the medieval cellars of the brewery. For this special Blend, the barrel selection is determined by De Halve Maan's brew masters, combining Bordeaux, Calvados and Rum barrel-aged Quadrupel with young Quadrupel. This special blend is then re-fermented in the bottle, allowing for even more complexity, fine effervescence, and an extended shelf life – this special beer will age nicely for up to 5 years. 25.4 oz bottle. 11% ABV.