The Magnum (9% alc. vol.) If you think that Magnum is just a Chimay Blue in a 150 cl (51 fl.oz.) bottle, you are forgetting one essential fact, for it is important to appreciate that a large volume of beer affects the development of taste in the second fermentation of the beer in the bottle and gives it a fuller and smoother character. A vintage like its little sisters of 33 (11.2 fl.oz.) and 75 cl (25.4 fl.oz.), Magnum Grande Réserve may be conserved in dark conditions for several years. This is how the beer acquires a light and pleasant taste of port. Convivial and festive, the Magnum is a must for the connoisseur who will not forget to serve his beverage at cellar temperature in "Gourmet" glasses (18 cl/6 fl.oz.).