Hertog Jan Dubbel is a traditional dark top-fermented beer . The term ' double ' refers historically to double the amount of ingredients we use in brewing. The secondary fermentation takes place in our Double on the bottle . This ensures that fresh rich flavor and fine aroma . Hertog Jan Dubbel taste with all your senses , allowing you to make the most of color, smell and taste. First, you pour it into a glass , you admire the foam and the beautiful reddish-brown color . Then you smell the full soft flavor . You take a sip and taste the rich malty character . Finally, you can enjoy the slightly sweet aftertaste.