Mostarda is not Mustard
The term mostarda is often source of misunderstandings, as it is sometimes used, by reference to the French “moutarde” or the English “mustard”, to define the best known condiment in Italian as mustard. Despite the Italian etymology, probably deriving from the Latin term mustum ardens (“burning” must, in the sense of “spicy”), refers both to the presence of must and spicy substances such as mustard. In fact, in various versions of Italian mustards either one or the other ingredient is often absent.
Nevertheless, Mostarda is a culinary product widespread in northern Italy and in Tuscany. It is made with different ingredients depending on the area of origin. These are preserves of one or more types of fruit treated, depending on the recipes, with sugar or honey, must or mustard distinctly.