Sugar
Sugar appears in 6 of the 123 recipes on Burgerman, roughly 5% of the library. In these builds it is a background ingredient that quietly decides texture in a lot of these builds. You will find it in McDonald's Big Tasty (Copycat), Homemade Smash Burgers and McDonald's Teriyaki McDouble (Copycat), among others. The highest-scoring recipe using it is McDonald's Big Tasty (Copycat) at 9.5 out of 10. It turns up most often alongside black pepper, ground beef, mayonnaise.
