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,
Plain loaf Plain loaf A plain loaf, slices of which are known in Scots as plain breid (pronounced ), is a traditional style of loaf made chiefly in Scotland and Ireland. It has a dark, well-fired crust on the top and bottom of the bread. There is no crust on the sides due to the unbaked loaves being stuck together in batches, baked together then torn into individual loaves afterwards. The term batch loaf is sometimes used. This style of bread does not fit well in most modern toasters due to the greater height of the loaf. This was once the more