Step 1

In a clean jar, combine the chiles, onion, horseradish, and garlic.

Step 2

In a separate vessel, make a brine by combining the water and non-iodized salt.

Step 3

Place a weight, if using, then pour the brine into the jar, leaving at least 1 inch of headspace. Screw the lid on tightly and store the jar at room temperature away from direct sunlight to ferment for two weeks. Burp (open, then close) the jar daily.

Step 4

Once fermentation is complete, strain the ferment, reserving ¾ cup of the brine.

Step 5

In a blender or food processor, combine the ferment, reserved brine, vinegar, mustard powder, sugar, turmeric, and salt. Blend until well combined.

Step 6

Keep the sauce stored in the refrigerator for up to 1 year.