Combine bourbon, water, and mustard seeds in bowl. Mix to wet all seeds. Let seeds soak anywhere from 4 hours to overnight, until most of the liquid is absorbed. (If time is an issue, you could also heat the mixture until it comes to a boil, remove from heat and then allow to steep for 2 hours)
Prepare canner, jars and lids.
Pour seeds and any remaining liquid into food processor. Process until fairly smooth.
Add vinegar, mustard powder, sugar and salt. Process briefly just to mix.
Transfer to saucepan.
Over medium heat, stirring constantly, bring to a boil. Continue boiling until it reaches your desired consistency for mustard. (Keep in mind that it will also thicken more upon cooling)
Remove jars from canner and fill leaving a ¼ inch headspace.
Make sure you remove any air bubbles in the jars. Wipe rims and affix lids.
Process in boiling water bath for 10 minutes.
Remove from heat and let rest in the hot water for 5 minutes.
Remove jars from water and store in a cool, dry place.
