With some mustards you can t really tell. Category fidelity is another criterion. Overall impressions is the third standard. The mustard must be balanced and have a good, long finish. Levenson explains that the finish or final impression of mustard can be as important it is with wine.
Bitterness is a common flaw, as is starchiness, a raw flour taste.
Some coarse grained mustards, those that use whole seeds, can taste gritty rather than grainy. In my own mustard competition, the popular Grey Poupon had a winy sweetness and was the mildest among seven Dijons tasted. At the other end of the spectrum was the sinus clearing Delouis, which finished third in the mustard championships. In between, Maille, Bornier, and Edmond Fallot were surprisingly mild. Roland Extra Strong was second to Delouis in strength, and Silver Palate came up creamy with just enough zip.