This homestyle yellow mustard recipe is an American classic.
INGREDIENTS: 1 cup cold water. 3/4 cup yellow dry mustard. 3/4 teaspoon coarse sea salt or kosher salt. 1/2 teaspoon ground turmeric. 1 teaspoon garlic purée, or 1/8 teaspoon garlic powder. 1/8 teaspoon paprika. 1/2 cup white distilled vinegar.
Place the water, dry mustard, salt, turmeric, garlic, and paprika in a small nonreactive saucepan and whisk until smooth. Cook the mixture over medium-low to low heat, stirring often, until it bubbles down to a thick paste, 30 to 45 minutes.
Whisk the vinegar into the mustard mixture and continue to cook until it’s thickened to the desired consistency—you know, the usual prepared mustard consistency, which ought to take anywhere from 7 to 15 minutes.
Let the mustard cool to room temperature. Transfer the mustard to an airtight container, cover, and refrigerate for up to 3 months. The mustard will be quite pungent the first few days or even weeks, but will mellow with time.