Raising Agents

The four ways a mixture is made to rise: chemical agents like baking powder, mechanical methods that trap air, steam from the moisture in a mixture, and biological raising with yeast.

⏱️ 16 min 🎯 14 activities

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What you'll cover

Making food rise

Cakes, breads and pastries would be flat and heavy without a raising agent. A raising agent makes a mixture rise by adding a gas, or by trapping one, that expands when the food is heated. As the food cooks, the mixture sets around the gas and holds the light, airy shape. There are four kinds of raising agent to learn.

Words for raising

Learn these four terms before you study the four kinds of raising agent.

Four kinds of raising

Every raising agent belongs to one of these four kinds.

Which gas, from which agent

A top answer names the correct kind of raising agent for the food and says which gas does the work. For bread, say yeast ferments to make carbon dioxide. For a whisked sponge, say air is trapped by whisking. Never just say the food rises when cooked.

Match the kitchen clue to the kind

chemical
mechanical
steam
biological

the mixture starts bubbling the moment liquid is added, so it has to be baked at once
the bowl has doubled in volume before the tin goes anywhere near the oven
nothing rises until the oven is very hot, and it sinks if the door opens early
the dough needs a warm hour on the side before it ever reaches the oven

Match the food to its raising agent

a loaf of bread
a whisked sponge cake
scones
choux pastry

yeast, a biological raising agent
air trapped by whisking, a mechanical method
baking powder, a chemical raising agent
steam from the moisture in the mixture

What does a raising agent do?

It makes a mixture rise using a gas that expands when heated.
It adds flavour to the finished dish.
It keeps the food safe to eat for longer.
It holds the ingredients together.

Spot the mechanical methods

Select the TWO mechanical methods of raising.

Whisking eggs and sugar to trap air.
Creaming butter and sugar together.
Adding baking powder.
Adding yeast.

Order the rising of bread

Put the steps of raising a loaf of bread with yeast in order, earliest first.

Mix yeast with warm water and sugar
The yeast ferments and makes carbon dioxide
The dough rises as the gas is trapped
Baking sets the structure and holds the rise

Summarise the raising agents

A _____ agent makes a mixture rise. A chemical raising agent such as baking powder produces the gas _____. A _____ raising agent traps air by whisking or creaming. Steam works because moisture in the mixture turns to _____ when it is very hot. A biological raising agent uses _____, which ferments to make gas.

raising carbon dioxide mechanical steam yeast chemical air oxygen flour sugar

Count the kinds

How many kinds of raising agent are there: chemical, mechanical, steam and biological?

Find the chemical agents

Tap the TWO chemical raising agents.

Baking powder
Yeast
Bicarbonate of soda
Whisked air
Steam

Which kind of raising?

Decide which kind of raising agent each one is.

Yeast is mixed into dough and left in a warm place to ferment
Eggs and sugar are whisked hard to trap air in a sponge
Bicarbonate of soda releases carbon dioxide as a cake bakes

Explain the rising

Choose a product such as bread, a whisked sponge or choux pastry. Explain which raising agent it uses and how that raising agent makes the product rise.

Name the product and its raising agent
Explain which gas is produced or trapped
Explain how the mixture rises and then sets