Mustard, of which there are about 10 billion varieties and brands on the market, is the product of two or three types of mustard seed – white and brown, and more rarely, black.

If the mustard seed is ground up, it is dry mustard. If the mustard seed is ground up and mixed with seasonings and water, wine, beer, must, or vinegar, it is "prepared mustard" or "made mustard."

If the seeds are not ground up, but are mixed with seasonings, water, wine, beer, must, or vinegar, they are whole grain mustard (Hint: this is what you are looking for, and yes, it is in a jar).

You may be wondering, why is the black mustard seed now more rarely used in the production of mustard than the white or brown? It is because the plant grows too tall and the seeds droop too much to be harvested mechanically in an economical way. Before the advent of mechanical harvesting, black seeds enjoyed their heyday. Now they are all but forgotten.