Once upon a time, soda bread was baked over hot coals in a covered skillet, trapping steam from the dough to produce a wonderfully crusty loaf of breada setup anyone can re-create in a dutch oven. Teamed up with low-protein all-purpose flour and volatile baking soda, buttermilk hits the sweet spot of gluten and carbon dioxide formation, creating a moist and fluffy soda bread that's chewy and crusty all at once.