Before the use of hops, brewers would try to preserve their beers and add enticing flavours to them by adding spice and herb combinations called variously gruit, gruyt, gruut or grut. British and Irish brewers also added a type of fine seaweed, called carrageen, or Irish moss, as much to clarify as to flavour them.
Coffee and dark chocolate flavours in a stout or porter can be conjured by preparing malt in particular ways, such as in a similar roaster to that used to make bakers’ cocoa or espresso coffees. A similar effect can be achieved by adding cocoa or ground coffee, which some brewers do. A few use instant coffee, or essence.
A novice may be forgiven for thinking that a barrel-aged beer will have been put in a barrel for the purpose of ageing. This is not correct. In modern brewing the term is used to describe a beer has been put into a barrel that previously contained some form of spirit or strong wine.