True soda bread is generally a very simple, rustic recipe with four basic ingredients: flour, buttermilk, salt, and baking soda. I like to add sourdough discard for a softer texture and slightly tangier flavor. Since this recipe calls for whole wheat, it can be helpful to add a little butter to keep it nice and tender. The raisins are totally optional! You can also add up to a tablespoon of sugar, chopped nuts, or other dried fruits for a sweet loaf. Citrus zest is quite nice, too! For a more savory option, add some caraway seeds instead.