Soda bread is popular in Ireland, where soft wheat grows much better than the gluten-heavy hard wheat.
This soda bread is a simple combination of cultured milk, flour, salt, and soda. A little butter gives the bread added moistness. This recipe can be made with spelt only, but when cut with rye flour it produces a more interesting loaf.
12 to 24 hours before baking, combine the flours in a medium bowl. Cut in the butter and drizzle in the buttermilk, then mix until completely combined. Cover, place in a warm spot, and allow to sit for 12 to 24 hours.
When ready to bake, preheat the oven to 350°F. While the oven is preheating, combine the salt and baking soda in a small bowl. Sprinkle the mixture over the soaked dough and knead it in for several minutes. You may need a bit of flour to keep the dough from sticking. Knead until the salt and soda are mixed in and the dough can be formed into a ball.
Place on a greased cookie sheet and cut a 1/4-inch X into the top with a sharp knife. Place in oven and bake 30 to 35 minutes, or until the loaf is golden-brown and has reached an internal temperature of 190°F.