Raising Agents

Raising Agents - Carbon Dioxide

Raising agents help cakes to 'rise' by producing gas which expands in doughs and mixtures when they're heated. Some agents add carbon dioxide.

Chemical raising agents

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.
Self-raising flours are made up of baking powder and plain flour.

Biological raising agents

Yeast is a microorganism that's used to help bread dough rise.
Yeast releases carbon dioxide and alcohol through the process of fermentation.
We usually have to prove doughs that contain yeast. This involves letting them stand in a warm environment to let fermentation happen.
During the proving process, the carbon dioxide that's released gets trapped and the dough rises.
When the dough is baked, the high heat kills the yeast and ends the fermentation process. Baking causes the carbon dioxide in the dough to expand (and the bread to rise) and the alcohol to evaporate.

Raising Agents - Steam and Air

Raising agents help cakes to 'rise' by producing gas which expands in doughs and mixtures when they're heated. Some agents produce steam or air.

Steam

When very liquidy mixtures (e.g. Yorkshire puddings) are cooked in hot ovens, water escapes as steam. The rising steam helps to raise the mixture.
The mixture bakes and solidifies as water escapes.
Any cold air that gets added (e.g. from opening the oven door) will sink the mixture.

Mechanical processes

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.

Mechanical processes (continued)

Beating adds air to mixtures very rapidly. Beating involves mixing ingredients with a spoon or fork.
If a whisk is used, we call this process whisking.

1Food Preparation Skills

1.1Food Preparation Skills

1.1.1General Practical Skills

1.1.2Knife Skills

1.1.3Preparing Fruit, Vegetables & Using Equipment

1.1.4Cooking Methods: Prepare, Shape & Combine

1.1.5Sauce Making, Tenderising & Marinating

1.1.6Dough & Pastry

1.1.7Shaping & Finishing Dough

1.1.8Raising Agents & Mixtures

1.1.9End of Topic Test - Food Preparation Skills 1

2Food, Nutrition & Health

2.1Macronutrients

2.1.1Proteins

2.1.2Proteins 2

2.1.3Fats

2.1.4Carbohydrates

2.1.5Carbohydrates 2

2.2Micronutrients

2.2.1Fat-Soluble Vitamins

2.2.2Water-Soluble Vitamins

2.2.3Minerals & Water

2.2.4Minerals & Water 2

2.2.5End of Topic Test - Macro & Micronutrients

2.3Nutritional Needs & Health

2.3.1Informed Choices for a Balanced Diet

2.3.2Informed Choices for a Balanced Diet 2

2.3.3Energy Needs

2.3.4Nutritional Analysis

2.3.5Diet Modifications

2.3.6Diet-Related Problems

2.3.7Diet-Related Problems 2

2.3.8End of Topic Test - Nutritional Needs & Health

3Food Science

3.1Cooking of Food & Heat Transfer

3.1.1Reasons for Cooking & Heat Transfer

3.1.2Water-Based Cooking Methods

3.1.3Fat-Based Cooking Methods

3.1.4Dry Cooking Methods

3.1.5Dry Cooking Methods 2

3.2Functional & Chemical Properties of Food

3.2.1Proteins & Carbohydrates

3.2.2Fats & Oils

3.2.3Raising Agents

3.2.4End of Topic Test - Food Science

4Food Safety

4.1Food Spoilage & Contamination

4.1.1Microorganisms & Signs of Food Spoilage

4.1.2Enzymes & Signs of Food Spoilage

4.1.3Food Poisoning

4.1.4Bacterial Contamination

4.1.5Microorganisms in Food Production

4.2Principles of Food Safety

4.2.1Temperature Control

4.2.2Ambient Foods & Food Labels

4.2.3Preparing, Cooking & Serving Food

4.2.4End of Topic Test - Food Safety

5Food Choice

5.1Factors Affecting Food Choice

5.1.1Factors Which Influence Food Choice

5.1.2Food Choices

5.1.3Religious Food Choices

5.1.4Food Labels

5.1.5Mandatory Food Labels

5.1.6Optional Food Labels

5.1.7Marketing Influences

5.1.8End of Topic Test - Food Choice

5.2British & International Cuisines

5.2.1British Cuisine

5.2.2Japanese Cuisine

5.2.3Japanese Ingredients & Dishes

5.2.4Spanish Cuisine

5.2.5Spanish Ingredients & Dishes

5.3Sensory Evaluation

5.3.1Taste Receptors & Olfactory Systems

5.3.2Sensory Testing Methods

5.3.3Sensory Testing Methods 2

5.3.4End of Topic Test - Cuisines & Senses

6Food Provenance

6.1Environmental Impact & Sustainability of Food

6.1.1Food Sources - Intensive & Organic Farming

6.1.2Food Sources - Genetically Modified Crops

6.1.3Food Sources - Reared Food

6.1.4Food Sources - Caught Food

6.1.5Food & The Environment

6.1.6Food & The Environment 2

6.1.7Sustainability of Food

6.1.8Sustainability of Food 2

6.1.9End of Topic Test - Environmental Impacts

6.2Food Processing & Production

6.2.1Primary Food Processing

6.2.2Primary Food Processing 2

6.2.3Secondary Food Processing

6.2.4Fortification

6.2.5Additives

6.2.6End of Topic Test - Food Processing & Production

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