56% hydration is intentionally low to create the dense, chewy crumb that defines a bagel. Malt syrup adds a slight sweetness and helps the glossy crust. Salt at 1.8% works because bagels are boiled in seasoned water.

Boiling gelatinises the starch on the outside before baking, which creates the chewy crust and shine. What you add to the water (baking soda, malt, etc.) changes the final result.