A leavening composition which gives an enhanced leavening and reduced use of acidulants comprises (1) an alkali metal bicarbonate, (2) at least 0.1 and preferably at least mole per mole of bicarbonate of a precipitant which is a water-soluble alkaline earth metal salt, and (3) optionally an acidulant, wherein (2) and (3) are present in a total amount from 105 to 800% of the stoichiometric amount that would be required to react fully with (1) in a boiling aqueous solution. In a preferred embodiment the acidulant forms a water insoluble calcium or magnesium salt and is sufficient to provide more than 0.105 g replaceable hydrogen per 100 mmol bicarbonate, and the precipitant is a water soluble calcium or magnesium salt which is capable of precipitating or complexing with said acidulant and is present in an amount sufficient to provide a final pH below 6.5 when the leavening agent is heated in a bakery mix, which allows the inclusion of an effective amount of a preservative.