Adapted from Design Sponge, makes 2 cups
1 cup ground mustard
1 cup apple cider vinegar
1 cup honey, additional to taste
1/2 teaspoon salt, optional
1/4 teaspoon ground pepper, optional
1 teaspoon ginger, optional
Combine all ingredients in a small pot. Bring to a simmer over medium heat, whisking gently.
Ladle into clean, sterilized jars with 1/2 inch of head space.
Mustard will last several weeks in the refrigerator or up to a year if hot water processed.