What does fats and oils when used to bake?
The main function of fat in baking is to retain the gases
released during baking. Fat also helps the browning of the
outside.
In bread making fat provides flavour but more importantly
lubricates the dough. This helps to retain the gases released
during baking thus ensuring a well risen loaf which will have a
soft crumb and will stay fresh longer.
Biscuits and pastry are made with "shortening ". The fat is
rubbed into the flour. The molecules of fat surround the flour
particles and exclude water. This prevents the development of
gluten in the dough. The fat is said to shorten the dough. A
increase in water in the mixture by using the wrong type of
margarine will encourage development of gluten, which will make
biscuits hard and pastry heavy and get soggy after baking.
In cakes fat has different functions as they are usually made by
either the creaming method or the all in one method. In the
creaming method the fat is beaten with the sugar until it becomes
light, fluffy and pale in colour as the sugar dissolves and air is
being incorporated increasing the volume. The air is important as
it makes places into which other gases, and water vapour from the
moisture and carbon dioxide from the baking powder, migrate and
expand on heating.
In the all in one method The fat has no aeration function but as
in bread making it will help to retain the gases released during
baking.