Seventy percent rye, scalded flour the night before, and a proof that stopped the moment the surface showed the first pinholes. The trick was the tin, not the recipe: a narrow one keeps the walls up while the crumb sets. Rested a full day before slicing, as rye wants.
A stiff feed at one part water to two parts flour, a clean jar, the back of the fridge. It came back sluggish and smelling of acetone, then two warm feeds later it doubled in five hours again. Less drama than the forums promise.
The dial says 230, the probe says 252. Every bake on this page was adjusted for that, which explains the dark bottoms in the spring posts. A pizza stone on the lowest rack evened it out more than any setting did.