This is a truly classic Irish (white) Soda Bread, no wheat flour here. This bread is almost cake like in texture. It's perfect to serve with a cup of tea or a bowl of soup!
You can either bake it on a rimless baking sheet or in a cast iron skillet for a very rustic bread.
Remember to wrap the bread in a clean dish towel as it cools. The steam will be trapped and that helps to soften the crust somewhat so that it isn't so hard.
3 1/2 cup all-purpose flour
2 - 3 T. sugar
1 1/2 t. salt
1 t. baking soda
1 1/2 - 1 3/4 cup buttermilk
Preheat oven to 425 degrees F.
In a large bowl, stir together the flour, sugar, salt, and baking soda.
Stir in enough buttermilk to make stiff dough.
Lightly flour a rimless baking sheet and turn out the dough onto it and shape it into a large round. Life it up onto a baking sheet and slash the surface with a sharp knife to make an "X" about an inch deep across the entire surface. OR you can place the dough into a greased cast iron skillet and, using the back of the spoon or spatula, smooth the dough. Follow instructions for marking with an "X."
Bake for 35 - 45 minutes, until golden and crusty. A tester should only have a few crumbs clinging to it, and the bread should sound hollow when the bottom is tapped. (If it doesn't, remove it from the baking sheet, turn it upside down directly on the oven rack and bake for 5 - 10 minutes more.)
Remove from the oven and wrap it in a clean tea towel and leave it, wrapped, to cool on a wire rack.
From Real Irish Food by David Bowers