Based on this recipe. I’m down to a couple servings of purchased mustard, but I have lots of mustard powder and yellow mustard seeds so I thought I’d make some. I only had a couple tablespoons of wine vinegar but I have loads of black vinegar since I only use small amounts of it in recipes occasionally. Balsamic vinegar is often listed as a substitute for black vinegar, so I thought I’d try doing the reverse substitution. It turned out nicely – a bit lumpier than commercial mustard, but good flavour.

  • 1/4 cup yellow mustard seeds
  • 1/4 cup water
  • 2 Tbsp white wine vinegar (5% or more acidity)
  • 2 Tbsp apple cider vinegar
  • 1 Tbsp black vinegar
  • 1/4 tsp salt
Put all the ingredients in a jar that can be well sealed with a tight-fitting plastic lid. (Don’t use metal because the acid in the vinegar will corrode it). Shake and then set in the fridge for 2 days. The seeds will absorb the liquid.
Pour into a blender and puree for a few minutes until reaching the desired level of graininess. Stir down a few times with a rubber scraper while processing. Add salt if needed. Taste it and see if you like it, otherwise set it aside for a few more days in the fridge and let it mellow and thicken. This keeps for several months in the fridge.