3.2.3
Raising Agents
Raising Agents - Carbon Dioxide
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.
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Chemical raising agents
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.
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Biological raising agents
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 - 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.
![Illustrative background for Steam](https://image-v2.cdn.app.senecalearning.com/2018-05/64675696-ccb9-4dbf-b55b-5910630f40e2/shutterstock_390252643,h_400,q_80,w_640.jpg)
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Steam
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.
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Mechanical processes
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.
![Illustrative background for Mechanical processes (continued)](https://image-v2.cdn.app.senecalearning.com/2018-05/a7703029-71a2-45ba-a65c-f282a87e5c67/shutterstock_722188429,h_400,q_80,w_640.jpg)
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Mechanical processes (continued)
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
2.2Micronutrients
3Food Science
3.1Cooking of Food & Heat Transfer
3.2Functional & Chemical Properties of Food
4Food Safety
4.1Food Spoilage & Contamination
5Food Choice
5.1Factors Affecting Food Choice
5.2British & International Cuisines
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
Jump to other topics
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
2.2Micronutrients
3Food Science
3.1Cooking of Food & Heat Transfer
3.2Functional & Chemical Properties of Food
4Food Safety
4.1Food Spoilage & Contamination
5Food Choice
5.1Factors Affecting Food Choice
5.2British & International Cuisines
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
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