The darker the mustard seed, the hotter and more flavorful it is. The heat of mustard seeds is caused by an enzyme called myrosinase. Myrosinase can be neutralized with heat. While black mustard is considered extremely hot when compared to the other varieties of mustard, it sweetens and becomes milder when it is toasted or fried. Heat gives it a nutty character.

The darker the mustard seed, the hotter and more flavorful it is. The heat of mustard seeds is caused by an enzyme called myrosinase. Myrosinase can be neutralized with heat. While black mustard is considered extremely hot when compared to the other varieties of mustard, it sweetens and becomes milder when it is toasted or fried. Heat gives it a nutty character.