Black mustard seeds are so widely used in cuisines from around the world that every serious cook should make an effort to keep them on hand. They are a flavorful addition to everything from salad dressings to dry rubs. If you cannot find them at your local grocery store and need them today, consider one of the alternatives below.
Your best bet: Brown mustard seeds
Brown mustard seeds are somewhat less spicy than black mustard seeds. While both the black and brown mustard varieties are used in Indian cooking, the brown is preferred to the black in Europe and America since it is possible to mechanize harvesting. As they do with black mustard seeds, Indian cooks usually fry brown mustard seeds in hot oil or ghee when using them in their dishes. With both types of mustard, frying or toasting eliminates some of the seed’s heat and gives it a nutty flavor. When mustard seeds are heated in oil or ghee, they pop after about 30 seconds depending on the oil’s temperature. Like black mustard, brown mustard contains antimicrobial compounds and can help to preserve chutneys and pickles.
Because brown mustard seeds are not as spicy as black mustard seeds, you may need to use more of them to get the same effect. Try using about 1 1/2 times the amount specified for black mustard in the recipe. Adjust to taste.
A decent second choice: White mustard seeds
White mustard is the mildest of the main types of mustard. It also has larger seeds than the brown or black varieties. It is the main form of mustard used in Europe and North America. It is also cultivated extensively on those two continents. White mustard seeds are used to make the bright yellow mustard that is traditionally applied to American hot dogs. The yellow color comes from the addition of food coloring or turmeric. Like both black and brown mustard, white mustard is used in Indian food as well. It is a useful spice for providing a milder mustard flavor.
When using white mustard in place of black, you will need to use considerably more to approximate the spiciness of black. Start by using twice the amount that your recipe indicates for black mustard and increase to taste.
In a pinch: Mustard powder
Mustard powder is simply ground mustard seeds and is often called ground mustard or mustard flour. It is usually made from yellow or brown mustard seeds. The mustard used to make prepared mustard is usually ground, which gives it its smooth texture. Ground mustard must be combined with a liquid to bring out its flavorful components.
Since ground mustard is typically made from yellow or brown mustard seeds, you can expect it to be less pungent than black mustard. The fact that it has been ground may also affect the intensity of its flavor. When using it as a substitute, start out at 1 1/2 times the amount that your recipe requires for black mustard seeds and increase to taste.
Mustard oil is pressed from the mustard seed and has many of the same flavor characteristics, including the heat. Like black mustard seeds, it is mainly used in Indian cooking. It can be used in salad dressings or poured over cooked vegetables. As with mustard seeds, heating mustard oil helps to eliminate some of the heat and gives it a nutty flavor.