When mustard powder is mixed with water, an essential oil is released through enzyme action, turning it into the pungent condiment we know and love, according to Dana Jacobi of Seven Spoons, a mustard manufacturer.

If you like your mustard as strong as possible, use dry powder and mix it with cool water (hot water will make it bitter) to make a paste just before serving. It's guaranteed to clear your sinuses.If you want to add any flavoring agents, such as salt or tomato paste, do so after about 15 minutes, when the mustard flavor has developed.

Vinegar, when used instead of water, will weaken the enzyme reaction and make a milder, less biting mustard.

Mustard has the useful property of stabilizing an emulsion, such as mayonnaise. A little bit of mustard in the egg yolks when making mayonnaise, for example, will help it to stay together.

If you're cooking with mustard, add it towards the end of the cooking time if you want to keep its pungency. If you'd like the flavor of mustard, but not the sharpness, add it when beginning a dish.

When French's first started making its mustard in 1904 it was called "Cream Salad Branc," because its primary use was for mixing with cream, as a salad dressing. Especially good on potatoes, it remains a good ideal. Here are some recipes for making your own mustard at home: DIJON-STYLE MUSTARD (Makes about 2 cups) 1/2 cup cold water 1 cup dry mustard powder 1 1/3 cups dry white wine 1 1/3 cups white wine vinegar 1/2 cup chopped onion 1/2 cup chopped shallots 1 tablespoon minced garlic 1 bay leaf 8 whole allspice 2 teaspoons salt 2 teaspoons sugar 1 teaspoon dried tarragon

Stir together the water and mustard powder. Let stand for 10 minutes.

In a noncorrosive saucepan, combine the white wine, white-wine vinegar, onion, shallots, garlic, bay leaf, allspice, salt, sugar and tarragon. Boil, uncovered, until reduced by half, about 15 minutes. (If you like your mustard hotter, reduce by a little more.)

Pour mixture through a wire strainer into the reserved mustard paste. Pour mixture back into the saucepan and cook over very low heat, stirring, for about 10 minutes, until as thick as heavy cream. Cool, cover and chill.

To make a herb mustard, stir in about 2 tablespoons fresh herbs as mustard comes off the heat. COARSE-GRAINED MUSTARD (Makes about 1 cup) 1/2 cup cold water 1/2 cup whole white mustard seeds 1 tablespoon dry mustard powder 1/2 cup white wine vinegar 1/2 cup dry white wine 1/2 cup chopped onion 1 teaspoon minced garlic 1 teaspoon salt 1 teaspoon sugar 1 bay leaf Pinch ground allspice

Mix together the water, mustard seeds and mustard powder. Set aside for at least 3 hours.

In a noncorrosive saucepan, combine the vinegar, wine, onion, garlic, salt, sugar, bay leaf and allspice. Simmer, uncovered on medium heat until mixture is reduced by half, about 10 minutes.

Pour mixture through a wire strainer onto the mustard seed mixture. Mix in a blender or in a food processor until coarsely ground.

Pour mustard back into the saucepan and cook over very low heat, stirring until mustard is thick, about 10 more minutes. Cool, cover and chill.