When the volume as well as the flavor of mustard is important to your recipe:
Mix 1 Tablespoon dried mustard, 1 teaspoon vinegar, 1 teaspoon cold water, and 1 teaspoon sugar to equal 1 Tablespoon of prepared mustard. Let stand 15 minutes to develop flavor and heat before adding to recipe. Sugar can be omitted but the result will be much hotter.
For additions to wet mixtures: 1 teaspoon dried mustard = 1 Tablespoon prepared mustard
Mustard Cooking Tips and Hints
• If your recipe calls for dark mustard seeds, you will be disappointed by substituting white ones. The flavor is truly that different, like night and day, and substitution is not recommended. When used whole in canning and preserving, the seeds do not impart a sharp mustard flavor, but add a nice, mild aroma.
• In India, the seeds are often toasted until they split open much like popcorn does. Beware overcooking the seeds as they will burn and turn bitter.
• Since heat causes the pungent flavor of mustard to dissipate, mustard is generally added near the end of the dish and gently heated.
• When adding mustard to baked goods, know that it will inhibit yeast growth, thus requiring longer rising periods. Use your imagination when adding mustards to recipes, but go easy and taste along the way. You can always add more, but there is no fix for going overboard.