Those who would never desecrate a hot dog with the “evil red stuff” might still think that it is otherwise acceptable to put k****** on hamburgers. No! But, don’t take our word for it. Check out page 35 of the May 2017 issue of REAL SIMPLE. The article “How to Win at Burgers” is unequivocal on the topic:
“MUSTARD, NOT KETCHUP. Mustard works with the flavor profile, not against it. (Ketchup is too sweet to complement beef.) Smear it on both top and bottom buns.”