I've messed around with this recipe alternating between making it with all purpose flour and a mix of all purpose, whole white wheat flour, and flaxseed. The regular loaf is definitely the best tasting, but if you want to be a little bit healthier feel free to play around with the flour you use since the recipe still works really well no matter the combination.
makes 2 loaves
4 tablespoons butter, melted
1 tablespoon sugar
2 teaspoons kosher salt
1 1/2 cups warm water
2 1/4 teaspoons instant yeast
4-4 1/2 cups all purpose flour or 2 cups all purpose and 2 cups whole white wheat
2 tablespoons ground flaxseed (optional)
1/3 cup baking soda
kosher salt for topping
In the bowl of a stand mixer with dough hook, combine butter, sugar, salt, and 1 1/2 cups warm water. Sprinkle the yeast on top and let sit 2-3 minutes. Add the flour and mix for 4-5 minutes or until dough forms a ball and pulls away from the bowl. Remove the dough from the bowl and place in a lightly oiled bowl. Cover dough with plastic wrap and a clean towel and then place in a warm draft free spot to rise for 1 hour. (I turn the oven on for 1-2 minutes and then turn it off and place the dough in the warmed oven.)
Preheat oven to 450°F and prepare a baking sheet with parchment paper. Fill a large pot with water and bring up to a boil. Divide the dough into two loaves and place on the baking sheet. Cover and let rest for 10 minutes but no longer than 30 minutes. Once the water is boiling, whisk in the baking soda and then gently place the two loaves in the water and cook for 30-40 seconds per side and then return loaves to tray and immediately sprinkle with kosher salt. Score the tops to create an X with a sharp knife. Bake in the preheated oven for 20-25 minutes. Remove and let cool 10 minutes before slicing.