Prior to the late 18th century, malt was primarily dried over fires made from wood, charcoal, or straw, and after 1600, from coke.
In general, none of these early malts would have been well shielded from the smoke involved in the kilning process, and consequently, early beers would have had a smoky component to their flavors; evidence indicates that maltsters and brewers constantly tried to minimize the smokiness of the finished beer.