François Bister's line of business in 1926 was roasting chicory. He bought a local mustard factory in 1930, and turned his attention to a jealously guarded recipe for L'Impériale mustard.
It used to be sent to grocer's shops in a large stoneware container where the grocer would use a ladle to fill the dishes brought in by their customers. With the advent of the self-service system, the "grenade-shaped" jars made an appearance. L'Impériale mustard jar has never changed and is just as popular as ever.
Jean Bister succeeded his father as manager the company and Fabienne Bister has since taken up the torch. Companies headed by the third generation are rather thin on the ground nowadays.