Bread in Europe They are very light, contain preservatives (e.g. ethyl alcohol) and have a very long shelf life (often more than a month). In Ireland it is traditionally held that the end of a loaf of bread (the "heel" of the loaf) is the best part of the loaf. Other stories and myths surround this piece of the bread in Irish mythology. Irish soda bread, developed to make the most of the soft wheat grown in Ireland, is unusual for a European bread in that it is a quick bread, using the reaction of buttermilk and baking soda rather than yeast to
Sodium bicarbonate and allow passages for steam to escape, so the breading is not blown off during cooking. Baking powder, also sold for cooking, contains around 30% of bicarbonate, and various acidic ingredients which are activated by the addition of water, without the need for additional acids in the cooking medium. Many forms of baking powder contain sodium bicarbonate combined with calcium acid phosphate, sodium aluminium phosphate, or cream of tartar. Baking soda is alkaline; the acid used in baking powder avoids a metallic taste when the chemical change during baking creates sodium carbonate. Sodium bicarbonate can be used to kill cockroaches.