Brown Mustard
Ein New Kochbuch. Marx Rumpolt. 1581, Transcribed by Dr. Thomas Gloning; Translated by Gwen Catrin von Berlin.

12. Braun Senff mit lauterm Essig angemacht/ ist auch gut.

12. Brown mustard made up with clear vinegar/ is also good.

1/2 C
Brown Mustard Seeds
2/3 C
Apple Cider Vinegar

Measure mustard seeds into a coffee grinder and process until as fine as desired. Transfer mustard to a food processor add vinegar, process until well combined. Transfer to a sealed container and allow to sit overnight.