Combine bread flour, rye flour, yeast, salt and caraway seed in a stand mixer fitted with a flat beater.
Add 1 1/2 cups warm water, oil and honey. Using low speed, beat just until combined.
Change stand mixer attachment to a dough hook. Using low speed, beat until dough is smooth and elastic, about 6 - 8 minutes.
Transfer dough to an oiled bowl; turn dough to coat with oil. Cover with plastic wrap. Let dough rise in a warm draft-free place until doubled in volume, about 1 1/4 - 1 1/2 hours.
On a lightly floured surface, roll dough into a 9x14 1/2 inch rectangle. Starting with a long edge, roll up dough, jelly-roll fashion, forming a loaf. Pinch dough along edge to seal.
Place loaf, seam side down, in a large parchment paper-lined rimmed baking sheet. Make angled score marks on top of loaf. Cover loosely with greased plastic wrap. Let rise in a warm draft-free place until doubled in volume, about 40 - 60 minutes.
Meanwhile, preheat oven to 350ºF. Whisk together egg and 1 tsp water until blended.
Uncover loaf and brush top with egg mixture.
Bake until loaf is golden brown, about 35 - 40 minutes.
Remove loaf from pan and cool on a rack. May be frozen.
Nutritional analysis per serving
*Ingredient not included in nutritional analysis.
66 calories, 1.2 g fat, 2.1 g protein, 11.7 g carbohydrate, 0.7 g fibre, 105 mg sodium