The primary ingredient in Irish soda bread is flour, specifically all-purpose flour. This traditional bread is unique because it relies on baking soda as a leavening agent instead of yeast. The use of baking soda, combined with buttermilk, creates a chemical reaction that helps the bread to rise. Irish soda bread is typically made with a few simple ingredients: flour, baking soda, salt, and buttermilk. Variations often include additions like raisins or caraway seeds. This bread is a staple of Irish cuisine and is cherished for its quick preparation and hearty texture.