The meatballs were a huge hit yesterday, but I felt there were too much cider vinegar, I would reduce to 3/4 cup cider vinegar + add 1/4 cup water. In my experience with sauce, it should be slightly thick, I added 2 tbsp cornstarch. Also, I think 4-5 tbsp mustard should be enough.
For the meatballs, I didn't put any milk, oil or mustard.
I liked the meatballs and would use them for other recipes. The sauce was good but we had leftovers and the longer they sat in the sauce the tangier they got they were not any good the next day. Too tangy.
The meatballs were very tender and tasty. The cider vinegar has a strong odor, but you cannot really taste it. I made the meat balls between 3/4" and 1" in diameter. I cooked them on two sides then added the sauce and simmered about 15 minutes. Very nice. I didn't track the time, but about an hour sounds right.
I liked this recipe, but would personally make some changes next time including the fact that I thought I was making the meatballs small enough but soon realized that they weren't when I got them on the skillet. Also, I would probably boil the meatballs instead of browning them and my taste tester (my fiance) prefers things a little more tart so I would us a little less brown sugar. All in all it was a VERY good and easy recipe.
I just finished making this, and it was really bad. My family could not eat it. There was too much ground mustard in the sauce and too much cidar vinegar. Plus, the meatballs did not need MORE mustard in them. We threw the whole thing away! What a HUGE waste of time and money. I'll never make this again.