The name mustard derives from the Latin words mustum (unfermented grape juice) and ardens (burning or fiery). Navarro's Medieval mustard is made in the ancient manner by mixing the hot seeds with the green must of Verjus. Mustard seeds and green grapes for Verjus are both harvested in late summer and have been blended for centuries. This is a coarse, savory mustard that will mind you of the origins of the more modern versions.