The holes make everything taste better
One of the reasons White Castle has such a distinct flavor (you can taste it in your mind right now, can't you?) is because the essence of the onions is contained in the steam that literally cooks the burger. All that flavor mixes together to give the patty one of the more unique profiles in all of fast foodom.
"We also realized that not only do these holes make things faster, but they were actually making our hamburger sandwiches taste better, too," Richardson said. "The holes let the patty capture even more of that flavor, and, when we put the bun on top of the patties on the grill for just a second, the steam travels through the onions and the patty and fuses with the bun."
That's why everything on a White Castle slider -- even the bun -- has that onion-y, meaty taste. Now you can see why Earl Howell was a first-ballot White Castle Hall of Famer.
"I guess you would call that flavor umami," Richard said. "But I just think it's White Castle."