Whisk all ingredients in a small saucepan until smooth

Bring to a slow boil over medium-high heat. Boil for 8 minutes, stirring every 30 seconds, so it does not stick to the pan.

Remove from heat and allow to cool to room temperature. Then cover with a lid and allow to cure for 8 to 10 hours on the counter before refrigerating or canning.

Transfer mustard to sterilized glass jars. Secure lid on jar.

Place jars in refrigerator for 24 to 48 hours before using

Mustard will keep up to a year in the refrigerator.

Spoon the mustard into jars that have been heated in boiling water, filling ¼ inch from the rim of each jar.

Using a non-metal utensil, remove any bubbles and add extra mustard if required.

Wipe rims with a damp cloth to remove any food residue.

Put on new clean rubber seals to the top of the jar. Clamp to secure. Or screw on rings if you are using that type of seal.

Place sealed jars into a water bath canner that is at 140 degrees. When boil returns, set timmer for 10 minutes and boil.

Turn off the heat source once the time is up. Remove jars from hot water after 5 more minutes. Cool jars overnight on a towel. Do not adjust lids during this time.

The next day, check jars have sealed before labelling and dating.

Allow to cure in the jars for a week before using.