How Do You Test if the Egg is Cooked?

Introduction: (Initial Observation)

You open the refrigerator to pick up a cooked egg and find out that all eggs are mixed up and you don’t know which one is the cooked one. Do you have any way to identify the cooked egg? Of course you can not break all eggs to find out which one is cooked. You need to do it without any damage to the eggs. To find out about inside condition of an object without breaking it can be very helpful for researchers. This is called a nondestructive test.

Information Gathering:

Find out about eggs and their changes when they are cooked. Read books, magazines or ask professionals who might know in order to learn about the effects of cooking on eggs. Keep track of where you got your information from.

Think yourself: What properties of egg may change after cooking? Have you seen people nock the wall to see if it is wood or plaster? Can you do the same for eggs? If you nock on the egg, do cooked eggs sound different than uncooked eggs? How about color, weight, smell… Do any of these properties change when the egg is cooked?

You may learn about a few methods while gathering information, but it is good if you also try to discover new ways of doing this.

Question/ Purpose:

What do you want to find out? Write a statement that describes what you want to do. Use your observations and questions to write the statement.

How do you test if the egg is cooked? The purpose of this project is to identify different methods that can be used to test an egg and see if it is cooked or not.

Our specific questions are:

Does cooking egg affect the amount of light passing through the egg?

Does egg spin easier and more when it is cooked?

Identify Variables:

When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other.

When we cook an egg, certain things will change. For a science experiment we call these things variables. When you cook egg you are changing an uncooked egg to a cooked egg. Since you choose the condition of egg, this is called an independent variable (or manipulated variable).

But there are other variables that depend on the condition of the egg and will change when you cook an egg. These are called dependent variables. For example the color of egg white is clear for uncooked egg, but it becomes white when you cook the egg. This is the way that you write it in your science project report.

For the first question:

Independent variable (also known as manipulated variable) is the egg condition. Possible values are: Uncooked, 1 minute cooked, 2 minutes cooked, ….,10 minutes cooked.

Dependent variable is the amount of light passing through the egg. This may be tested using a light box and ranked visually.

Constants are the type and the initial conditions of the eggs.

For the second question:

Independent variable (also known as manipulated variable) is the egg condition. Possible values are: Uncooked, 1 minute cooked, 2 minutes cooked, ….,10 minutes cooked.

Dependent variable is the number of turns an egg spin when spun by hand. Independent variable may also be the number of seconds the egg continues to spin.

Constants are the type and the initial conditions of the eggs.

Hypothesis:

Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis.

Two or three possible hypothesis are proposed here, but you can have your own hypothesis. You only need one hypothesis unless you want to test different possible methods.

My hypothesis is that more light will pass through an uncooked egg and we can test it using a light box or strong flashlight.

My hypothesis is that cooked egg will spin or roll easier than uncooked egg.

My hypothesis is that a cooked egg sounds different when you knock at it.

Experiment Design:

Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a “control.” A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral “reference point” for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a “controlled experiment.”

Experiment 1:Does cooking egg affect the amount of light passing through the egg?

Introduction: If the amount of light passing through the egg changes as we cook the egg, we can use light as a measure to test the egg and find out how well it is cooked.

In this experiment we use a light box to see how much light passes through an egg. We try this with raw egg, cooked egg and eggs cooked for different lengths of time such as one minute, 2 minute, 3 minutes, 4 minutes and 5 minutes. In these cases we will start timing as soon as water starts to boil.

You will need: (Adults help is required to prepare the light box)

• One cooked egg
• One raw egg
• additional eggs cooked from 1 to 5 minutes
• One metal, wooden or cardboard box with a round hole about 1 inch diameter.
• A light inside the box facing the hole.

Procedure:

1. Place the uncooked egg on the hole and turn on the light. Try to memorize the amount of light that passes through the egg.

2. Turn off the light. Replace the egg with a cooked egg. Turn the light back on and see the light that passes through the egg. Do you see any difference?

3. Repeat the above procedure with egg samples cooked for 1 to 5 minutes. Do you see any difference?

Record your observations:

Can this method be used to test the egg? Can this method be used for other tests? Can you use this method to say if there is a chicken in the egg?

If you visually compare and rank the amount of light passing through the egg, you may write your results in a table like this:

Rank the light passing through a raw egg as 10. Also rank the light passing through a well cooked egg as 1. Visually compare and rank the light passing through for the eggs cooked for 1 to 5 minutes.

Note that you are not using a light meter, so the numbers 1 to 10 do not represent any of the light measurement units. These are just relative estimates based on your observations.

Draw a graph:

Use your results table to draw a bar graph. Make 7 vertical bars and name them 0,1,2,3,4,5 and 10. Each bar represents one cooking time. The height of each bar will represent the light passing through based on your visual estimate. (use 1 inch for each number; so the height of bar for uncooked egg will be 10 inches.)

Experiment 2: Does egg spin easier and more when it is cooked?

Introduction: If the time an egg continues to spin when spun by hand changes as we cook the egg, we can use this to test the egg and find out how well it is cooked.

• • 7 eggs
  • A plate or a flat surface
  • A watch that can measure seconds.

Procedure:

1. Leave one egg uncooked

2. Place 6 eggs in a cooking pan and add water enough to cover the eggs. Start the heat. Wait until water starts to boil. As soon as water starts to boil, take the time and remove one egg every one minute until only one egg is left. Wait an additional 5 minutes for the last egg and then remove the last egg. Use a marker to label the eggs from 1 to 5 for the eggs that were boiling 1 to 5 minutes. Label the last egg as 10 because it was boiling for 10 minutes. Label the uncooked egg with 0.

3. Wait until the eggs cool off. Place the eggs one at a time in a plate or a flat surface and spin them as fast as you can. Measure and record the number of seconds each egg spins. For best results you may repeat each spin test 3 times and record the average in your results table.

Record your observations:

Can this method be used to test the egg? Can this method be used for other tests? Can you use this method to say if there is a chicken in the egg?

You may write your results in a table like this:

Draw a graph:

Use your results table to draw a bar graph. Make 7 vertical bars and name them 0,1,2,3,4,5 and 10. Each bar represents one cooking time. The height of each bar will represent the number of seconds an egg continued to spin after you spun them hard.

Experiment 3:  Does egg spin easier and more when it is cooked?

In this experiment we turn or roll the eggs to see if cooked egg spins or rolls different from an uncooked egg. We try to use this method to see if an egg is cooked or not.

You will need:

One cooked egg
One raw egg

Procedure:

1. Spin each egg in turn on a plate. The egg that continues to spin for a longer time is the cooked one.

2. Now spin the eggs again, then quickly stop both of them. Then let go of both eggs. You will see that the cooked egg stays still but the raw one starts spinning again.

Why?
The contents of the egg have more inertia* when they are raw, because they are in the form of a liquid. This inertia slows down the raw egg and that is why it stopped spinning before the cooked egg. In step 2, the liquid in the raw egg was still moving when you stopped both eggs, so that movement made the raw egg begin to spin again.

* The tendency of a body to resist acceleration; the tendency of a body at rest to remain at rest or of a body in straight line motion to stay in motion in a straight line.

Materials and Equipment:

List of material can be extracted from the experiment section.

Results of Experiment (Observation):

Experiments are often done in series. A series of experiments can be done by changing one variable a different amount each time. A series of experiments is made up of separate experimental “runs.” During each run you make a measurement of how much the variable affected the system under study. For each run, a different amount of change in the variable is used. This produces a different amount of response in the system. You measure this response, or record data, in a table for this purpose. This is considered “raw data” since it has not been processed or interpreted yet. When raw data gets processed mathematically, for example, it becomes results.

Calculations:

No calculation is required for this project.

Summary of Results:

Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.

It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.

Conclusion:

Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did.

Sample conclusion:

Hard cooked egg spin when you give them a turn; raw ones stop after a turn and a half or so.

Also write why do you think that an uncooked egg can not turn? is it because the liquid inside does not turn?

You will need to write more conclusions depending on your experiments and hypothesis.

Related Questions & Answers:

What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.

Possible Errors:

If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.

If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.

References:

Visit a local library and see some books in food and cooking section. Look for testing eggs. A librarian may be able to help you in locating the right book. There are also many books about eggs as well as egg production and quality control. You may find some of such books in www.Amazon.com or www.bn.com.
Following are some web resources:

http://www.urbanext.uiuc.edu/eggs/act00.html

http://www.ucmp.berkeley.edu/vertebrates/tetrapods/amniota.html

http://www.uen.org/Lessonplan/preview.cgi?LPid=5010