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 amounts of product are further obtained by solution mining, pumping heated water through previously mined nahcolite beds and reconstituting the dissolved nahcolite above ground through a natural cooling crystallization process. Currently, only Genesis Alkali (formerly Tronox, formerly FMC) in the Green River Wyoming basin has successfully commercially solution mined the product. Sodium bicarbonate, as "bicarbonate of soda", was a frequent source of punch lines for Groucho Marx in Marx brothers movies. In "Duck Soup", Marx plays the leader of a nation at war. In one scene, he receives a message from the battlefield that his general is reporting a gas