Dish · german
Brezel
A yeasted dough twisted into its knot shape, dipped in a lye or baking soda solution before baking for a dark, glossy, chewy crust and coarse salt on top.

Where it comes from
The dip, historically food-grade lye rather than the milder baking soda most home bakers use, is what gives the crust its dark color and flavor, a caustic step handled with care in professional bakeries.
What cooks argue about
A real lye bath gives the deep mahogany color bakeries rely on but is dangerous to handle at home, so most home versions substitute a baking soda bath that browns lighter and milder.
Versions
Nobody has published a brezel here yet. When somebody cooks one from a video and publishes it, their version appears in this list, with a link back to the original.
What goes in it
Each one opens everything else made with it.