Step 1

Mix the mustard seeds with cider vinegar and water in a non-reactive glass dish.

Step 2

Allow them to soak and ferment at room temperature for 2 days.

Step 3

After soaking, add in the salt and any additional flavours (see the section above for options).

Step 4

Using a blender or an immersion blender, grind the seeds to the desired consistency. Add water if more liquid is required. The exact amount of liquid will depend on how finely ground the mustard is.

Step 5

Store in a glass jar in the refrigerator. Allow the mustard to mellow for at least 2 weeks before using. It should last in the fridge for at least 6 months.