Boiling before baking
Most people know that the right way to make bagels is to boil them first and then bake. This allows the dough’s shape to set and get a bit chewy, and when you bake them there will be less expansion which means the bread is denser. So you get a dense bread with chewy inside and crisp outside. Bagels are also traditionally boiled in water with malt syrup instead of plain water.
Pretzels are similar: they are traditionally dipped in lye solution prior to baking. This gives them their characteristic flavor and color, but lye is kind of scary because it’s really caustic (lye is just NaOH, which can be used to clean drains – that’s how caustic it is). As it turns out, if you want to make soft pretzels at home you can approximate the effect by boiling in water with baking soda.