dry mustard
Also known as: mustard powder
Ground mustard seed, sold as a fine powder -- sharp and pungent on its own, but once moistened (by a liquid in a recipe) it develops the familiar tangy mustard bite. Used in small amounts in sauces, dressings, and cheese dishes, where it adds a background sharpness without the vinegar and other flavorings that prepared mustard carries.
Buying guidance
Sold in the spice aisle in a small tin or jar; Colman's is a well-known brand. Any brand works the same way, since it's just ground mustard seed.
Substitutions
- Prepared yellow or Dijon mustard -- use about 3 times the amount of dry mustard called for, and reduce another liquid slightly to compensate for the added moisture and vinegar.
- A different ground spice with some pungency, like wasabi powder -- not a true flavor match, but shares the sharp, sinus-clearing quality in tiny amounts.
- Omit entirely -- the dish loses a background sharpness but is otherwise complete.
Tips & common mistakes
It needs a few minutes of contact with liquid to develop its characteristic bite -- added and used immediately, it can taste flatter or more bitter than if given a little time to bloom.
Storage
Keeps for a year or more in a sealed container away from heat and light; like other ground spices, it gradually loses potency rather than spoiling.