BAKING POWDER AND BAKING SODA
Baking Powder and Baking Soda are leavening agents which means they can be
used to make baked products 'rise'. It's useful to understand the difference
between these ingredients to ensure you get the results you expect.
When baking soda (Sodium Bicarbonate) comes into contact with an acid it reacts
quite vigorously and gives of tiny bubbles of Carbon Dioxide. Like any gas,
these bubbles expand when heated so if the baking soda is evenly distributed for
example throughout a cake mix, it will 'rise' during baking. However, we
need to be clear here, if no acid is present, there will be no reaction and
consequently no 'rise'.
So, baking soda can be used when the mixture it is being added to, is acidic
in nature perhaps through the addition lemon or other citric juice or sometimes
even vinegar. If baking soda is added to a mixture which is not acidic, it will
have no effect (except perhaps to give the end product a fairly unpleasant soapy
Baking powder on the other hand is a mixture which contains its own supply of
acid in the form of 'Cream of Tartar' (Potassium Bitartrate - an acidic salt) as
well as Baking Soda so as soon as the power becomes wet, the reaction starts and
carbon dioxide gets produced. Baking powder has a third component, Cornstarch
which simply helps to stabilise the product and keep it dry so the two main
constituents don't react until needed.
NB: There is always some liquid water available in dough's and batters
etc. to get the baking powder reaction going (for example, egg whites are 90%
When leavening with Baking Powder or Baking Soda, there is some urgency to
getting your mixture baking quickly to ensure that as little of the gas as
possible escapes from the mix. If the batter is left to stand too long the rise
may not be as good as it could be and the end product will be rather dense.
To counteract this problem to some degree, double action Baking powders are
now available. They are called double action because they have an addition
acid added which are only activated at higher temperatures once the baking
process starts. This means its not quite so critical to get a product into the
oven quickly. The higher temperature acids are often metallic salts (for
example; sodium aluminum sulfate) and some bakers believe these double action
powders can give the final product a slightly metallic taste and so prefer not
to use them.
NB: To confirm the effectiveness of baking powder which may have been sitting
in the cupboard for a long time, place a teaspoon of the powder into a small
container of hot water. If it fizzes energetically, it is still active and
Baking powder is usually used at the rate of 1 teaspoon per cup of flour in
If you don't have baking powder to hand, here is an acceptable recipe to
create your own:
2 tbsp of cream of tartar (The acid component which reacts with baking soda to
produce carbon dioxide)
1 tbsp of baking soda
1 tbsp of cornstarch - Acts as a stabilising and drying agent to prevent the
other 2 components reacting before they are supposed to.