Great Science Fair Experiments
Baking is a Science
Steps in a Great Science Fair Experiment.
Step 1: Get an Idea. This can be hard. Think of something you enjoy and then begin to ask how what sciences are used to make it happen. The kitchen is a great place to start. There is science in any food preparation task. Chemical and physical changes, bacteria and fungus at work-even packaging and sensory preferences are sciences.
In baking many baked products rely on leavening to "lighten" the end product.
Three common types of leavening include: Chemical, yeast fermentation and air suspended in the batter through beaten egg whites.
Step 2. Define the problem. What do you want to find out? For example, in baking, you might ask "What is the purpose of using a certain ingredient, method or temperature? " What will happen if.?"
Choose one factor or condition that you will intentionally change (independent variable) that will influence the result (dependant variable).
||Baking powder batter reaction
||Yeast in mixtures
||Egg white temperature
||Volume of beaten egg whites
Your experiment will also need one or more variables called controlled variables that are not changed throughout the experiment. You must use controls in order to truly know which variable affected the outcome of your experiment. If you vary two factors at once, you will not know which variable had the most effect.
Examples of controlled variables:
- Baking powder is reacts to produce CO2 gas which lightens or "leavens" many baked goods. Baking powder is "double acting." Half its reaction is due to moistening the batter and causing the acidic agent to react with the alkaline agent. The other half occurs when the batter reaches a certain temperature. To find that temperature, the amount of baking powder and liquid it is mixed with must remain constant and the temperature changed to find when the second reaction will occur.
- Yeast is a living, microscopic organism-a fungus-that when mixed with water that is not too hot and certain other ingredients will grow in a fermentation process. The fermentation process releases carbon dioxide that will leaven or "raise" a dough or batter. Other ingredients in yeast and water mixtures have an effect on the rate of fermentation. To observe this, you would need to control the amount and type of yeast used, the temperature at which the experiment is conducted, and the volume of water in the mixtures.
- Recipes frequently instruct you to have the egg whites at room temperature before beating them. What will happen if temperatures vary? The mixing tools (bowl, beaters) will need to be at the same temperature, the same volume of egg whites used and the mixing period timed to see what differences occur in volume between refrigerated egg whites and room temperature egg whites.
Step 3: Research
Look up information about your topic and your variables. This information will later be used to write your report. Use at least three different sources including books, magazines, Internet, interviews, encyclopedias. Be sure to write down information for your Bibliography.
For leavening Internet research:
Home Baking Association -- www.homebaking.org
American Egg Board -- www.aeb.org
Clabber Girl -- www.clabbergirl.com
Fleischmann's Yeast -- www.breadworld.com
Red Star Yeast Corporation --www.redstaryeast.com
Sarah Phillips, Baker -- Baking911.com
Cooking Wizardry for Kids. Margaret Kenda and Phyllis S. Williams. Barron's Educational Series. 1990.
Rising to the Occasion. Fleischmann's Yeast/National 4-H Council. 1999. www.breadworld.com
See for Yourself. More than 100 Experiments for Science Fairs and Projects.
Vicki Cobb. 2001. Scholastic Inc.
TIP: Don't forget to check with your school's Family & Consumer Sciences classroom! Refer to their Food Science text such as Chapter 14-"Leavening Agents and Baked Goods" from Food Science and You by Kay Mehas and Sharon Rodgers.
Step 4: Hypothesis.
The hypothesis is a special kind of prediction that forecasts how one variable will affect a second variable. A hypothesis should be written as an if/then statement.
- If a batter containing baking powder is mixed with cool (72 degree F.) ingredients, then it will not loose volume before it can be baked and the end product will have more volume.
- If active dry yeast is mixed with water and salt then it will not ferment as well as when combined with flour or sugar initially.
- If egg whites are used directly from the refrigerator then they will not provide as much volume to lighten or leaven a batter.
Step 5: Test and Experiment
- Write a list of materials needed to perform the experiment.
- Write your procedure-a list of numbered, detailed directions that tells
- every step of your experiment. Another person should be able to pick up your written procedure and perform the same experiment without your assistance.
- Prepare a chart or grid to note your observations and collect data. Your
- data should be expressed as quantitative data-numerical values. This will allow you to graph your results.
- Note qualitative observations too! These are what the investigator
experiences with their senses while observing.
- Note temperature of ingredients (use a probe food thermometer available at most stores that sell kitchen equipment) in degrees F.
- Note the temperatures of refrigerated ingredients, those at room temperature and liquids used in mixtures of yeast.
- Measure ingredients on a scale or liquids in milliliters so each mixture contains the same amount of ingredients.
- Measure the height of a batter, mixture or finished product in centimeters using a grease-free stick or probe measure.
- Time all mixing procedures in seconds, using the same speed on a mixer and same length of time for accurate comparisons.
- Yeast fermentation may be observed by preparing one package (7 gm/1/4 oz.) active dry yeast with one cup 105 degree F. water in one of three or four clean, 16 oz. soft drink bottles. A funnel will help you add the ingredients. Add one teaspoon of an independent variable (salt, sugar, flour, oil) in each bottle. Attach one balloon (use the same size on each bottle), securing with a small rubber band at the bottle neck. Label each bottle according to its contents. Time the lengths between each observation point.
Step 6: Organize Data and Make Conclusions
- Record your results in full-make charts, graphs, and diagrams, using a computer or graph paper.
- Label and title all charts, graphs and diagrams for interpretive ease.
- Analyze the results and form a conclusion.
- Tell whether your conclusion supported your hypothesis.
Step 7: Write your report.
Use paragraph form and the six traits of good writing:
- Tell what you wanted to accomplish (problem, variables and hypothesis)
- How you did it (procedure-all steps of the scientific method)
- What you discovered (project results and research)
- Acknowledgements and bibliography
Step 8: Visual Display.
A visual display is summary of your project. Use eye-catching colors, words, graphs and pictures, but not too cluttered. It's the scientific content that's important.
||Illustrations / Photos
||Graphs / Charts