Soak the mustard seeds in the vinegar and water, making sure the seeds are covered by the liquid. Leave soaking overnight.
Add the sugar and honey to the seeds mixture. Blend mixture until it reaches desired consistency, adding water if needed.
Ladle into quarter pint jar leaving 1/4" headspace and process in water bath for 15 minutes. The mustard will at first seem extremely spicy, but will mellow out after about a week.