I keep seeing dry mustard as an ingredient in mac & cheese.
Since it tastes pretty bad directly, what is it that it adds to Mac & cheese or any other dish as an ingredient? Sharp? Spicy? Umami?
Besides a bit of flavor, the lecithin helps to emulsify the sauce.
That’s also why some salad dressings use a bit of mustard when mixing oil and vinegar.
We also add a small amount of nutmeg. Anybody else?
It adds sharpness. Most commercial cheese is rather dull these days, and the dry mustard helps brings that sharp element back to the dish. I’m not really sure which part of Mac & Cheese would need help emulsifying, though.
FWIW, I don’t put dry mustard in my mac and cheese, but just about anything that is white-sauce based, including mac and cheese, gets a pinch of nutmeg. Seems to deepen the flavor. My hubby saw me putting nutmeg in the creamed spinach on Thanksgiving, and said “Why in the hell would you put nutmeg in spinach??”
He just doesn’t get it. 
FWIW, I don’t use dry mustard in my mac & cheese since the only thing I can find around here is karashi and I’m not sure how that would taste. I’ve never noticed any significant difference in the flavor.
Why would you want to ruin perfectly good nutmeg? :dubious:
Hey, no need to tell me, friend! I don’t even like creamed spinach. I was making it because he likes it! When I told him I’ve always put nutmeg in his creamed spinach, he was all like 
Didn’t keep him from eating all of it, though.
A bit of nutmeg is a small price to pay for a happy marriage! 
Yep, and a bit of cayenne - I skip the mustard.
This is a good thing. We used to make pasta with a smoked salmon white sauce sauce. Just a bit of ground nutmeg made the dish.
I just made a casserole today from eggs, sausage, bread, milk and cheese and it called for dry mustard. I thought the same thing as the OP… “mustard?” 
Didn’t taste the mustard one bit, fwiw.
I put dry mustard in my meatloaf, and while it doesn’t make it taste mustardy, we sure miss it when I forget. And another meatloaf-y type thing I make, which is basically meatloaf inside a loaf or French bread ( and called, amazingly, Burger Loafer) has nutmeg. Definitely not as good without it.