Soda bread versions are unleavened, but from the early 19th century bannocks have been made using baking powder, or a combination of baking soda and buttermilk or clabbered milk. Before the 19th century, bannocks were cooked on a bannock stone (Scots: stane), a large, flat, rounded piece of sandstone, placed directly onto a fire, then used as a cooking surface. Several varieties of bannock include Selkirk bannocks, beremeal bannocks, Michaelmas bannock, Yetholm bannock, and Yule bannock. The traditional soda farl is used in the full Scottish breakfast along with the potato scone (Scots: "tattie scone"). In Serbian tradition, soda bread is prepared
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.