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
Bicarbonate to some organisms or can make other chemical constituents such as ammonia toxic. In darkness, when no photosynthesis occurs, respiration processes release carbon dioxide, and no new bicarbonate ions are produced, resulting in a rapid fall in pH. The most common salt of the bicarbonate ion is sodium bicarbonate, NaHCO, which is commonly known as baking soda. When heated or exposed to an acid such as acetic acid (vinegar), sodium bicarbonate releases carbon dioxide. This is used as a leavening agent in baking. The flow of bicarbonate ions from rocks weathered by the carbonic acid in rainwater is an important