It's best to leave any preconceptions at the door when it comes to soda bread, because they're probably wrong. This is especially true when it comes to ingredients. Colman Andrews, editorial director at The Daily Meal and author of The Country Cooking of Ireland, writes, "True soda bread is the simplest of things: bread made with nothing more than flour, salt, sour milk or buttermilk, and — in place of yeast — baking soda, which reacts with the milk to have a leavening effect."
What many Americans have experienced, though, is basically cake. It's got raisins or currants and it's softened up with eggs. This is fine, but should really be called spotted dog or railway cake, says Andrews, not soda bread, or traditional Irish soda bread.
Robert Ditty's grandmother used to always tell him to leave out the buttermilk overnight so that it would be at room temperature before mixing with the other ingredients.
Flour right out of the bag tends to contain lumps, which can affect the ratios of ingredients when mixed together. So it's best to sift it into a bowl before using.
Kneading for too long will lead to tough, chewy bread. Ditty kneads for only two minutes in his recipe.
For the perfect crust, use a heavy cast-iron skillet.
If you really do want raisins in your soda bread, no one's going to stop you. But do it right: soak them in water first to soften.
We've said it over and over again, and this time is no exception. Invest in an oven thermometer. Your oven's actual temperature can differ from its stated temperature by up to 75 degrees Fahrenheit or more, especially if it's older. This can lead to baking times that diverge widely from the stated time in the recipe.
At long last, here is Robert Ditty's recipe.