Quick bread leavening agents include a weak base, such as baking soda (sodium bicarbonate) plus a weak acid, such as cream of tartar, lemon juice, or cultured buttermilk, to create an acid–base reaction that releases carbon dioxide. (Quick bread leavened specifically with baking soda is often called "soda bread".) Baking powder contains both an acid and a base in dry powdered form, and simply needs a liquid medium in which to react. Other alternative leavening agents are egg whites mechanically beaten to form stiff peaks, as in the case of many waffle recipes, or steam, in the case of cream puffs. Nevertheless,
Crumpet If differentiated from the crumpet, a pikelet is defined as containing no yeast as a raising agent and as being cooked without a ring, making it rather flatter or thinner than a crumpet, and a thinner batter was also used. In Stoke-on-Trent, pikelets were once sold in the town's many oatcake shops. A 1932 recipe for Staffordshire pikelets specifies that they were made with flour and buttermilk, with bicarbonate of soda as a raising agent, and suggests cooking them using bacon fat. The term "pikelet" is used in Australian and New Zealand cuisine for a similarly flat cake, of the