Can You Substitute Dry Mustard for Prepared Mustard?

It used to be that there were a very few mustards in common usage: the dry stuff and the ever-present yellow bottle of prepared mustard. Not anymore. It's not usual to have dozens of mustards on the supermarket shelves vying for your attention. But the ultimate decision is up to you. If your recipe calls for prepared mustard, AKA the wet stuff, you can substitute dry mustard, but only after you adjust the amount of mustard and add a bit of liquid.

The Basics

Ground up mustard seed is the main ingredient in prepared mustard. But a tablespoon of ground mustard is much hotter than a tablespoon of prepared mustard, which often includes other ingredients, such as vinegar, turmeric, paprika, salt, and garlic.

As a rule, use 1 teaspoon of dry mustard for each tablespoon of prepared mustard called for in your recipe. You also will need to use water or vinegar to make up for the lost liquid because of the swap of ground mustard for the prepared ingredient called for in your recipe.

For each teaspoon of ground mustard, include 2 teaspoons of liquid. If you use just water, your mustard will most likely be bitter. Try using a teaspoon of water and 1 teaspoon of vinegar. Even white distilled vinegar works, but a wine vinegar will cut some of the heat and pungency.

Stir your mixture into a paste in a nonmetallic bowl and let it sit at room temperature for at least 30 minutes. The acid in the vinegar helps to mellow out the heat of the mustard.

You could also add a teaspoon of sugar or less, depending on your taste, or sweeten your homemade prepared mustard with honey.

Increasing the Content

If you need more than a tablespoon of mustard, combine the following ingredients in a nonmetallic bowl. Avoid the metal because it may interact with your ingredients and leave an unpleasant aftertaste. 

• 4 teaspoons mustard powder
• 1 tablespoon water
• 1 tablespoon white wine vinegar
• 2 teaspoons honey
• 1/4 teaspoon salt

Stir the mixture into a paste and let it sit for about an hour. It will make about 1/4 cup.

Take Time to Experiment

Note that while these techniques will function in a pinch, they are only mustard shortcuts. The best homemade mustard starts with whole mustard seeds. You can find fresh mustard seeds at major groceries, and until the seeds are ground, they will last far longer than store-bought prepared mustard.

You can spice up your ground mustard by adding herbs or spices to your mustard seeds and grinding the entire concoction in a coffee grinder or using a mortar and pestle. You will still need a liquid to make the prepared mustard, though. Swap out wine for water for a creamy Dijon.

If you want more heat in your mustard, add a pinch of wasabi or horseradish root. Really, the flavor you want is up to you.

If you're still a bit timid about creating your own mustard recipes, here's a simple recipe for homemade Dijon-style mustard.