Cheddar Rye Sandwich Loaf with Glossy Crust

Steps

1. Cube the cheddar and chill it while you make the dough; soften the butter and beat the egg in a small bowl, then refrigerate the egg for the glaze.
2. In a large bowl, whisk the rye flour, bread flour, instant yeast, salt and black pepper.
3. Stir the molasses into the lukewarm water, then pour the molasses water into the rye flour and bread flour mixture and mix into a shaggy, sticky dough. This is about 66% hydration and 1.8% salt.
4. Set aside about one fifth of the softened butter for greasing the pan. Add the remaining four fifths of the butter to the dough and knead with wet hands or a mixer for 8 minutes until smooth but still tacky; rye dough stays sticky, so avoid dusting with more rye flour or bread flour.
5. Pat the dough into a rectangle and scatter the cheddar over it; fold and knead gently for 1 minute until the cheddar is evenly distributed.
6. Cover and let rise at about 75°F (24°C) for 60 to 75 minutes, until puffy and about 1 1/2 times its size.
7. Grease a 9x5-inch loaf pan with the reserved butter. Shape the dough into a tight log, tucking in any exposed cheddar, and set it seam-side down in the pan.
8. Cover and proof at about 75°F (24°C) for 45 to 60 minutes, until the dough crowns just above the rim and springs back slowly when poked. Meanwhile, preheat the oven to 375°F (190°C).
9. Brush the top with the beaten egg for a golden, glossy crust.
10. Bake 40 to 45 minutes, until deep golden and 190°F (88°C) in the center; tent with foil after 25 minutes if browning fast.
11. Turn the loaf out and cool fully on a rack, about 1 1/2 hours, before cutting into 12 slices.