CARDIFF, WALES—At the Experimental Archaeology Conference earlier this month, archaeologists Merryn and Graham Dineley asserted that features of Viking settlements previously believed to be bathhouses might actually have been used to brew beer. Their hypothesis is based on the excavation of a stone structure dating back nine centuries at Cubbie Roo’s Castle on the Scottish archipelago of Orkney that, according to their interpretation, included what could be a mash oven and several drains. Further, the stone constructions are often located right next to what are known to be the Viking ceremonial drinking halls.