Source: https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-2-3-raising-agents [Revision notes](https://senecalearning.com/en-gb/revision-notes.md) › [GCSE](https://senecalearning.com/en-gb/revision-notes/gcse.md) › [Food Preparation](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation.md) › [AQA](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa.md) › Raising Agents # Raising Agents Food Preparation & Nutrition: AQA GCSE, topic 3.2.3 ## 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 ![Chemical raising agents](https://image-v2.cdn.app.senecalearning.com/2018-05/d310dac7-f90f-4a34-96eb-b5d09160041b/shutterstock_529813615.jpg) - 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 ![Biological raising agents](https://image-v2.cdn.app.senecalearning.com/2018-05/a59c55fb-59a2-4395-bd2c-5ef720b5cc14/shutterstock_642103714.jpg) - 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 ![Steam](https://image-v2.cdn.app.senecalearning.com/2018-05/64675696-ccb9-4dbf-b55b-5910630f40e2/shutterstock_390252643.jpg) - 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 ![Mechanical processes](https://image-v2.cdn.app.senecalearning.com/2018-05/2ab7c0b2-d178-46d5-b58b-37dd9da2d8fe/shutterstock_137252393.jpg) - 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) ![Mechanical processes (continued)](https://image-v2.cdn.app.senecalearning.com/2018-05/a7703029-71a2-45ba-a65c-f282a87e5c67/shutterstock_722188429.jpg) - 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. ## Test yourself on Raising Agents - What type of raising agent is yeast? - What are the ingredients of baking powder? - Making Bread with Yeast - What do we call it when ingredients are mixed with a spoon or a fork? - Which of the following processes does NOT add air to mixtures? [Practise this topic for free](https://app.senecalearning.com/classroom/course/d59d0e60-4fa8-11e8-bbba-738ab127bed6/section/632d00e0-58ec-11e8-ad04-2d6b280873e2/session) - Previous topic: [3.2.2 Fats & Oils](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-2-2-fats-and-oils.md) - Next topic: [3.2.4 End of Topic Test - Food Science](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-2-4-end-of-topic-test-food-science.md) ## Food Preparation & Nutrition: AQA GCSE contents ### 1 Food Preparation Skills - 1.1 Food Preparation Skills - [1.1.1 General Practical Skills](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/1-1-1-general-practical-skills.md) - [1.1.2 Knife Skills](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/1-1-2-knife-skills.md) - [1.1.3 Preparing Fruit, Vegetables & Using Equipment](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/1-1-3-preparing-fruit-vegetables-and-using-equipment.md) - [1.1.4 Cooking Methods: Prepare, Shape & Combine](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/1-1-4-cooking-methods-prepare-shape-and-combine.md) - [1.1.5 Sauce Making, Tenderising & Marinating](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/1-1-5-sauce-making-tenderising-and-marinating.md) - [1.1.6 Dough & Pastry](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/1-1-6-dough-and-pastry.md) - [1.1.7 Shaping & Finishing Dough](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/1-1-7-shaping-and-finishing-dough.md) - [1.1.8 Raising Agents & Mixtures](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/1-1-8-raising-agents-and-mixtures.md) - [1.1.9 End of Topic Test - Food Preparation Skills 1](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/1-1-9-end-of-topic-test-food-preparation-skills-1.md) ### 2 Food, Nutrition & Health - 2.1 Macronutrients - [2.1.1 Proteins](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-1-1-proteins.md) - [2.1.2 Proteins 2](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-1-2-proteins-2.md) - [2.1.3 Fats](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-1-3-fats.md) - [2.1.4 Carbohydrates](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-1-4-carbohydrates.md) - [2.1.5 Carbohydrates 2](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-1-5-carbohydrates-2.md) - 2.2 Micronutrients - [2.2.1 Fat-Soluble Vitamins](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-2-1-fat-soluble-vitamins.md) - [2.2.2 Water-Soluble Vitamins](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-2-2-water-soluble-vitamins.md) - [2.2.3 Minerals & Water](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-2-3-minerals-and-water.md) - [2.2.4 Minerals & Water 2](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-2-4-minerals-and-water-2.md) - [2.2.5 End of Topic Test - Macro & Micronutrients](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-2-5-end-of-topic-test-macro-and-micronutrients.md) - 2.3 Nutritional Needs & Health - [2.3.1 Informed Choices for a Balanced Diet](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-3-1-informed-choices-for-a-balanced-diet.md) - [2.3.2 Informed Choices for a Balanced Diet 2](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-3-2-informed-choices-for-a-balanced-diet-2.md) - [2.3.3 Energy Needs](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-3-3-energy-needs.md) - [2.3.4 Nutritional Analysis](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-3-4-nutritional-analysis.md) - [2.3.5 Diet Modifications](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-3-5-diet-modifications.md) - [2.3.6 Diet-Related Problems](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-3-6-diet-related-problems.md) - [2.3.7 Diet-Related Problems 2](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-3-7-diet-related-problems-2.md) - [2.3.8 End of Topic Test - Nutritional Needs & Health](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/2-3-8-end-of-topic-test-nutritional-needs-and-health.md) ### 3 Food Science - 3.1 Cooking of Food & Heat Transfer - [3.1.1 Reasons for Cooking & Heat Transfer](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-1-1-reasons-for-cooking-and-heat-transfer.md) - [3.1.2 Water-Based Cooking Methods](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-1-2-water-based-cooking-methods.md) - [3.1.3 Fat-Based Cooking Methods](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-1-3-fat-based-cooking-methods.md) - [3.1.4 Dry Cooking Methods](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-1-4-dry-cooking-methods.md) - [3.1.5 Dry Cooking Methods 2](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-1-5-dry-cooking-methods-2.md) - 3.2 Functional & Chemical Properties of Food - [3.2.1 Proteins & Carbohydrates](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-2-1-proteins-and-carbohydrates.md) - [3.2.2 Fats & Oils](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-2-2-fats-and-oils.md) - [3.2.3 Raising Agents](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-2-3-raising-agents.md) - [3.2.4 End of Topic Test - Food Science](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/3-2-4-end-of-topic-test-food-science.md) ### 4 Food Safety - 4.1 Food Spoilage & Contamination - [4.1.1 Microorganisms & Signs of Food Spoilage](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/4-1-1-microorganisms-and-signs-of-food-spoilage.md) - [4.1.2 Enzymes & Signs of Food Spoilage](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/4-1-2-enzymes-and-signs-of-food-spoilage.md) - [4.1.3 Food Poisoning](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/4-1-3-food-poisoning.md) - [4.1.4 Bacterial Contamination](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/4-1-4-bacterial-contamination.md) - [4.1.5 Microorganisms in Food Production](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/4-1-5-microorganisms-in-food-production.md) - 4.2 Principles of Food Safety - [4.2.1 Temperature Control](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/4-2-1-temperature-control.md) - [4.2.2 Ambient Foods & Food Labels](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/4-2-2-ambient-foods-and-food-labels.md) - [4.2.3 Preparing, Cooking & Serving Food](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/4-2-3-preparing-cooking-and-serving-food.md) - [4.2.4 End of Topic Test - Food Safety](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/4-2-4-end-of-topic-test-food-safety.md) ### 5 Food Choice - 5.1 Factors Affecting Food Choice - [5.1.1 Factors Which Influence Food Choice](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-1-1-factors-which-influence-food-choice.md) - [5.1.2 Food Choices](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-1-2-food-choices.md) - [5.1.3 Religious Food Choices](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-1-3-religious-food-choices.md) - [5.1.4 Food Labels](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-1-4-food-labels.md) - [5.1.5 Mandatory Food Labels](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-1-5-mandatory-food-labels.md) - [5.1.6 Optional Food Labels](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-1-6-optional-food-labels.md) - [5.1.7 Marketing Influences](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-1-7-marketing-influences.md) - [5.1.8 End of Topic Test - Food Choice](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-1-8-end-of-topic-test-food-choice.md) - 5.2 British & International Cuisines - [5.2.1 British Cuisine](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-2-1-british-cuisine.md) - [5.2.2 Japanese Cuisine](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-2-2-japanese-cuisine.md) - [5.2.3 Japanese Ingredients & Dishes](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-2-3-japanese-ingredients-and-dishes.md) - [5.2.4 Spanish Cuisine](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-2-4-spanish-cuisine.md) - [5.2.5 Spanish Ingredients & Dishes](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-2-5-spanish-ingredients-and-dishes.md) - 5.3 Sensory Evaluation - [5.3.1 Taste Receptors & Olfactory Systems](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-3-1-taste-receptors-and-olfactory-systems.md) - [5.3.2 Sensory Testing Methods](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-3-2-sensory-testing-methods.md) - [5.3.3 Sensory Testing Methods 2](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-3-3-sensory-testing-methods-2.md) - [5.3.4 End of Topic Test - Cuisines & Senses](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/5-3-4-end-of-topic-test-cuisines-and-senses.md) ### 6 Food Provenance - 6.1 Environmental Impact & Sustainability of Food - [6.1.1 Food Sources - Intensive & Organic Farming](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-1-1-food-sources-intensive-and-organic-farming.md) - [6.1.2 Food Sources - Genetically Modified Crops](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-1-2-food-sources-genetically-modified-crops.md) - [6.1.3 Food Sources - Reared Food](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-1-3-food-sources-reared-food.md) - [6.1.4 Food Sources - Caught Food](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-1-4-food-sources-caught-food.md) - [6.1.5 Food & The Environment](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-1-5-food-and-the-environment.md) - [6.1.6 Food & The Environment 2](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-1-6-food-and-the-environment-2.md) - [6.1.7 Sustainability of Food](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-1-7-sustainability-of-food.md) - [6.1.8 Sustainability of Food 2](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-1-8-sustainability-of-food-2.md) - [6.1.9 End of Topic Test - Environmental Impacts](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-1-9-end-of-topic-test-environmental-impacts.md) - 6.2 Food Processing & Production - [6.2.1 Primary Food Processing](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-2-1-primary-food-processing.md) - [6.2.2 Primary Food Processing 2](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-2-2-primary-food-processing-2.md) - [6.2.3 Secondary Food Processing](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-2-3-secondary-food-processing.md) - [6.2.4 Fortification](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-2-4-fortification.md) - [6.2.5 Additives](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-2-5-additives.md) - [6.2.6 End of Topic Test - Food Processing & Production](https://senecalearning.com/en-gb/revision-notes/gcse/food-preparation/aqa/6-2-6-end-of-topic-test-food-processing-and-production.md)