The Maillard Reaction (pronounced my-YARD), named after ... Initial Phase: When food is heated, sugars (like glucose or fructose) and amino acids (the building blocks of proteins) react.

Not all sugars are affected by the Maillard reaction; only reducing sugars, like the simple-structured types of lactose or glucose, transform. And crucially, there needs to be intensive heat.

A slice of toast with burnt edges, smeared with jam. Charred vegetables from the grill. Burnt-to-a-crisp marshmallows ...