Cake Making And Raising Agents

Question 1

When cake making what does flour do?

Answer 1

Forms the structure of cake:

As the cake is heated the protein sets the framework

Question 2

What does dextrinisation mean?

Answer 2

A browning that occurs when starch is converted to sugar

Question 3

What is the function of fat?

Answer 3

Adds colour and flavour
Holds air bubbles-which makes volume
Produces short crumb

Question 4

What is the function of sugar?

Answer 4

Sweetens and adds flavour
Holds air in mixture when creamed with fat
Caramelisation give colour

Question 5

What does aerate mean?

Answer 5

Introduce air

Question 6

What is the function of raising agents?

Answer 6

Aerates mixture increasing volume

Question 7

What is the function of eggs?

Answer 7

Traps air when whisked
Holds fat in emulsion and keeps it stable
Adds colour and flavour

Question 8

What does it mean when a cake has a peaked cracked top?

Answer 8

Oven temperature was too high

Over mixing

Question 9

What does it mean when a fake has a heavy texture?

Answer 9

Too much liquid

Too little leavening

Question 10

What does it mean if fruit has sunk in a fruit cake?

Answer 10

Too runny mixture

Question 11

What does it mean when a cake has sunk in the middle?

Answer 11

Oven door has been opened

Too much raising agent

Question 12

What does it mean when a cake has a course texture?

Answer 12

Too much raising agent

Question 13

What does it mean when a cake has a sugary speckled crust?

Answer 13

Too much sugar

Question 14

What does it mean when a cake is very dry?

Answer 14

Not enough liquid

Over cooked

Question 15

What are the gas bubbles in raising agents?

Answer 15

A mixture of
Air
Carbon dioxide
Steam

Question 16

How is carbon dioxide given off?

Answer 16

Yeast in bread
Bicarbonate of soda added to cake or scone mixtures
Baking powder, which has bicarbonate of soda in it and is added to self -raising flour by food manufacturers
Steam, water in a gaseous state

Question 17

Name three ways gases are introduced into mixtures

Answer 17

Chemical - using baking powder or bicarbonate of soda go produce C02 gas
Mechanical - by whisking, beating, creaming etc.
Biological - using yeast to produce C02 gas

Question 18

How does raising agents work?

Answer 18

The action of moisture, heat or acidity triggers a reaction with the raising agent to produce the gas bubbles
As a cake mixture, batter or dough cooks, the gas bubbles given off by the raising agent make it rise by expanding and pushing it
Gas bubbles then become set in and provide the soft, sponge like texture

Question 19

Explain how creaming causes a cake to rise

Answer 19

When fat and sugar are beaten together lots of air bubbles are trapped in the mixture
Each bubble is surrounded by a thin layer of fat
The mixture changes colour during creaming as trapped air creates a foam
Egg is added to the mixture to coagulate and form a wall round the air bubbles so they expand and raise the mixture
The mixture sets as the egg proteins coagulate and starch granules in flour completely expand as as it sets, air escapes from mixture

Question 20

What is carbon dioxide gas produced by?

Answer 20

Bicarbonate of soda and yeast

Question 21

If bicarbonate of soda is used on its own in a mixture, what will happen?

Answer 21

They would rise well but the taste of the washing soda produced in the reaction would be very unpleasant

Question 22

What is the reaction by bicarbonate of soda is used on its own in a mixture?

Answer 22

Bicarbonate of soda + heat —> washing soda + carbon dioxide gas + water

Question 23

To prevent the washing soda taste of bicarbonate of soda, what must be done?

Answer 23

Bicarbonate of soda is mixed with an acid called cream of tartar to make baking powder
If you put an acid and an alkali, C02 gas will be produced, but the acid and alkali will neutralise each other, so that you do not get washing soda produced

Question 24

What is the reaction when cream of tartar is added to a mixture

Answer 24

Bicarbonate of soda + cream of tartar + heat —> sodium potassium tartrate + carbon dioxide gas + water

Question 25

Explain how Yeast acts as a raising agent

Answer 25

C02 gas will make the bread dough expand and rise when it is left in a warm place
When bread is being made and dough is left to rise, Yeast cells multiply (budding)
This means there are more yeast cells to produce C02 so the bread will rise and expand well
When bread is put in the oven, the C02 gas bubbles expand with heat and steam and alcohol are produced as dough heats up
The alcohol evaporates in the heat of the oven when the loaf is baked so there is no alcohol left when the bread comes out of the oven
Yeast cells will die if they come into direct contact with salt or boiling water

Question 26

What are chemical raising agents?

Answer 26

Bicarbonate of soda is an alkali raising agent that breaks down when it’s heated. Carbon dioxide bubbles form and, when they expand, cause a mixture to rise.
Baking powder contains both bicarbonate of soda and an acidic substance called cream of tartar. Heating baking powder sparks a neutralisation reaction

Question 27

How do mechanical processes act as raising agents?

Answer 27

We can fold air into doughs and mixtures by:
Literally folding pastry doughs into layers. Air gets trapped between folds.
Using the folding technique for mixtures. This involves using a spatula or spoon to cut through the mixture and pour it over itself to trap air.
Sieving ingredients like flour traps air between individual particles.
Creaming adds air.
Rubbing fat into flour introduces air between individual flour particles