Prepared mustard condiments can be made either from whole seeds or from powdered mustard, also called mustard flour, which has been ground and sieved to remove the seed coat. Dry mustard seeds and their powder are not pungent. Their pungency develops over the course of a few minutes or a few hours when the seeds are soaked in liquid and ground, or the preground seeds are simply moistened. The combination of moisture and cell damage revives the seeds’ enzymes and allows them to liberate the pungent compounds from their storage forms. Most prepared mustards are made with acidic liquids—vinegar, wine, fruit juices—which slow the enzymes, but also slow the later disappearance of the pungent compounds as they gradually react with oxygen and other substances in the mix.