What pearl-like ingredient caramelizes on the outside of a Liège waffle?

Pearl sugar is the pearl-like ingredient that caramelizes on the outside of a Liège waffle. These hard sugar pieces are folded into the enriched dough rather than simply sprinkled on top.

A Liège waffle uses a dense, brioche-like yeast dough, unlike the lighter pourable batter used for a Brussels waffle. During cooking, the pearl sugar partly melts and browns against the hot iron. This creates the waffle’s characteristic caramelized patches, crunchy edges, and chewy texture.

Pearl sugar is especially useful because its larger crystals resist dissolving too quickly in the dough. Powdered sugar, caster sugar, and ordinary brown sugar behave differently: they dissolve more readily and do not produce the same embedded caramel crunch.

Liège waffles are traditionally smaller, rounded, and often eaten plain, since the dough and caramelized sugar supply much of the flavor. Toppings may be added today, but they are more associated with Brussels-style waffles and international café versions.