I don't know about the rest of you, but I've never thought mustard had much of a kick. I knew American yellow mustard was considered bland compared to other mustard. I tried using Coleman's English mustard powder to make some, and likewise thought it had much less zing than pepper, black or red. There's a local company that makes a coarse Belgian brown mustard that does have some bit, but not much.
The other day I happened on an article describing mustard varieties. It mentioned that most off the shelf mustards had vinegar in them because that prolonged the shelf live, but it also decreased the heat. The article also said that black mustard crushed and mixed just w. water and left to sit for about 15 minutes produced the hottest.
Went to an Indian grocery store, and bought 14 oz. of black mustard seed for less than $4. Crushed some in a mortar last night, and gave it a splash of water. waited a few minutes.
When I went to sample it, I was startled. My nose began to tingle, my eyes to water, and then I sneezed. I took a small piece of ham from the 'fridge, and dipped into the mustard mash. In the pic above, you can see the small indent at the bottom of the mustard mass.
It was easily as hot as fresh horse radish, maybe even wasabi. !!! and the little bits stuck between my teeth kept my mouth burning for a few hours.
This morning it had mellowed, but still was hot enough that a tiny bit on some eggs was distinct.
Read some more, and found that mustard is the strongest anti-bacterial. I could see how a rub with this in it would clean the outside of a piece of meat.
Also, came across an old Roman recipe that mixed it with grape must, and almond and pine nut paste. Have to try that next.
Guess this goes to show that it is often true that making something fresh from scratch will yield flavors beyond enything off the shelf.