Practices, recipes and supply of a late medieval brass foundry: The refractory ceramics and the metals of an early 15th century AD metallurgical workshop in Brussels

•First evidence of medieval brass production in Brussels.•One of the rare 15th century mass-production metallurgical workshops known in Europe.•Refractory clays for crucibles are imported from the Mosan valley to Brussels.•Recipes are documented by petrographic and EDS analyses.