• Home   /  
  • Archive by category "1"

Hard Boiled Eggs How To Know When Done With Your Homework

Text and photos by Lindsey Johnson for Design Mom.

In March and April, eggs go on sale at the market, so this is an ideal time to learn, or improve, our egg boiling skills. You may have big plans to dye some Easter eggs, or maybe you’re just craving an egg salad sandwich. Either way, knowing how to perfectly hard-boil an egg is a skill everyone should have.

Do you ever peel and cut open an hard-boiled egg only to find a pesky grey-green ring around the yolk, or that the yolk is still a little raw? I’m here to help!  And soon you’ll be an egg-spert and be able to show all your friends how easy it is to hard-boil eggs.

Put the eggs into a deep pot in a single layer. Secret #1: Fill the pan with cold, not hot, water. The goal here is to bring the eggs up to boiling temperature along with the water, which will also help prevent cracking and promote even cooking. The eggs should be covered by 1-2 inches of water. To measure, dip your finger in and touch an egg. If the water reaches anywhere between your first and second knuckle, you’re probably good to go. If not, add a little more.

Bring the water up to a boil. Secret #2: Let the eggs boil for one minute, then cover and remove from heat. The heat in the water will continue to cook the eggs after they are off the burner. If you have an electric stove with coil burners, you can skip boiling the eggs for one minute because the burner will retain heat. Let the eggs sit in the covered pot for 12- 15 minutes.

Secret #3: The actual time is going to vary a bit due to the size of the eggs. Medium eggs will take less time, about 9 minutes, and extra large eggs will take more time, about 15 minutes. The altitude where you live will affect the cooking time as well. I live at about 5,000 ft. above sea level, so I keep the eggs cooking in the covered pot a few minutes longer so the yolks aren’t too raw. Plan on practicing with a few small batches till you get the timing just right.

If you’re boiling a lot of eggs at one time, sometimes it’s worth sacrificing one egg to ensure the others are properly cooked. Remove one egg from the pan, cool it as quickly as you can in ice water, peel it and cut it open to see if it’s cooked all the way. Undercooked yolks are almost as bad as overcooked ones! They will be darker yellow and look raw.  If your tester egg isn’t cooked through yet, keep the rest of the eggs cooking in the hot water for a few minutes longer. (Alas, there’s no going back once the yolk is overcooked.)

Next step is Secret #4: To stop the cooking (and avoid over-cooking) you’ll need to cool the eggs quickly. There are two options. You can gently drain off the hot cooking water and add cool water to the pan. Or, you can remove the eggs from the hot water with a slotted spoon and carefully transfer to a bowl of cool water. As I mentioned, this stops the cooking process, so be sure not to skip this step.

Now we’ve come to the funnest part: peeling. Secret #5: Cold eggs peel much more easily than warm or room temperature eggs. Begin cracking the cooled egg by rolling it gently against a flat surface, like a counter or cutting board. Go ahead and roll until the entire shell is covered in cracks. Then carefully peel the shell off. If the shell sticks to the egg white, help things along by either peeling under cold running water or in a bowl of water. I have also found that cracking the larger bottom end first, then rolling can help the shell come away more easily. Be sure not to crack it too hard or you’ll chance breaking the egg white right in half!

Peeled eggs should be used very soon after peeling. Unpeeled eggs should be kept in a container with a lid (to prevent odors) in the fridge for up to a week.

TROUBLESHOOTING

Peeling
Have you followed all the tips and you’re still having a hard time peeling the egg? It might be because your eggs are too fresh. (Too fresh? Who knew that being fresh could be a problem?) Fresh eggs are known to be harder to peel, and that includes those fresh from the farm. Eggs in the store are typically about a week old, so plan ahead. The fix: Let your eggs sit in the fridge for a few days or even two weeks before you boil them. Or try the pin trick I mention in a bit…

Cracking
If your eggs are cracking during the boiling process, try this: add a little vinegar or salt to the water. The vinegar/salt will help any escaping egg whites coagulate and stop leaking out of the crack.

Or, you can follow my Mother’s tip: prick the bottom of the egg, where there’s a tiny space between the membrane and the shell. The idea is to release a little bit of air. It’s supposed to help prevent cracking — and some people swear it makes peeling easier too!

Grey-Green Ring on the Yolk
Found a grey-green ring? Don’t worry it’s not dangerous and doesn’t affect the taste of the egg. It’s just a little unappealing. That dark colored ring is a natural reaction between sulfur and iron reacting at the surface of the yolk and the egg white. It does mean that your hard-boiled eggs cooked for too long. Make a note of how long the eggs cooked and cook them for a few minutes less the next time.

And that’s it! Now those hard-boiled eggs are ready for Grandma’s Deviled Eggs, dyeing with the kids, or eating as a quick snack or breakfast on the run.

Now, please tell me, do you have any tips you’d add to mine? Have you ever tested and timed your eggs so that you know the exact amount of cooking time for your stove and elevation? I’d love to hear.

P.S. — Save those shells! They can add extra calcium and other nutrients to your garden.

P.P.S. — Love secrets? Find all the posts in this series here.

Difficulty
Time RequiredShort (2-5 days)
PrerequisitesAccess to a stove top
Material Availability Readily available
CostVery Low (under $20)
SafetyAdult supervision is required. Exercise caution when working with a stove top. There is a chance that eggs can carry a bacteria called Salmonella. Salmonella can cause severe food poisoning. The Centers for Disease Control and Prevention (CDC) recommend avoiding eating eggs unless the whites and yolks are both firmly cooked. For this reason, we do not recommend eating the soft-boiled eggs in this science project; just make observations. If you would like to eat them, consider doing your science project with pasteurized eggs.

Abstract

Sometimes on a busy day, it is hard to get things done. The rush to get things done can start first thing in the morning, when you are so busy getting ready and gathering your homework, that you barely have time for breakfast. It takes time to get a nutritious meal ready. But, eggs are a perfect choice for breakfast because they can be cooked quickly and in many different ways. A soft-boiled egg is a choice that many people make. They like the way the thickened, tasty yolk coats their hash browns or toast. In this cooking and food science fair project, you will determine the best recipe for producing consistent, soft-boiled eggs that will get your day off to a great start!

Objective

To scientifically determine the best method for consistently producing the best soft-boiled egg.

Credits

Michelle Maranowski, PhD, Science Buddies

Cite This Page

MLA Style

Science Buddies Staff. "Egg-cellently Cooked Eggs: The Process of Soft-Boiling an Egg" Science Buddies. Science Buddies, 28 July 2017. Web. 14 Mar. 2018 <https://www.sciencebuddies.org/science-fair-projects/project-ideas/FoodSci_p046/cooking-food-science/soft-boiling-eggs>

APA Style

Science Buddies Staff. (2017, July 28). Egg-cellently Cooked Eggs: The Process of Soft-Boiling an Egg. Retrieved March 14, 2018 from https://www.sciencebuddies.org/science-fair-projects/project-ideas/FoodSci_p046/cooking-food-science/soft-boiling-eggs



Last edit date: 2017-07-28

Share your story with Science Buddies!

Yes,I Did This Project! Please log in (or create a free account) to let us know how things went.

Are you planning to do a project from Science Buddies?

Come back and tell us about your project using the “I Did This Project” link for the project you choose.

You’ll find a link to “I Did This Project” on every project on the Science Buddies website so don’t forget to share your story!

Got itRemind me later

Introduction

The typical egg packs a lot of punch in a small package. One large egg has about 75 calories and 13 essential nutrients, including high-quality protein, various vitamins, choline, folate, riboflavin, and multiple minerals (including zinc and iron). Eggs can help you maintain muscle strength, as well as promote a healthy pregnancy, brain function, and eye health. Eaten in moderation, eggs have shown no link to cardiovascular disease or stroke in a healthy population, according to some studies. The egg is a nutrient-dense food product that is eaten by people all over the world. In fact, humans have been eating eggs for thousands of years. Egyptian and Chinese records show humans eating eggs in 1400 BC.

There are about 200 breeds of chickens around the world today. Most of the eggs eaten in the United States are from the Single-Comb Leghorn breed. The United States produces 75 billion eggs per year! What is really amazing is that most eggs reach the supermarket just a few days after being laid.

The main components of an egg are the shell, the air cell, the albumen (or egg white), and the yolk. The yolk contains all of the fat of the egg, most of the vitamins and minerals, and about half of the protein. The albumen or egg white is mostly water (about 90 percent) and protein (about 10 percent). People who are limiting their fat intake can eat egg whites, since egg whites contain no fat.

There are several methods for preparing eggs. Eggs can be scrambled, poached, fried, pickled, hard-boiled, and soft-boiled. In a raw egg, the proteins in the egg are folded and curled up tight, but when you cook an egg by heating it, the heat causes the proteins in the egg to uncurl so that they interact with each other, forming a network of connected proteins. This is why an egg changes how it does when you cook it. You have probably often heard of hard-boiled eggs, but what is a soft-boiled egg? The white of a soft-boiled egg is firm, but the yolk is between runny and solid. It should be viscous, or thickened and sticky. In this cooking and food science project, you will develop a recipe for creating the best soft-boiled egg in the least amount of time. You will experiment with three different cooking methods: (1) cooking the egg in boiling water, (2) steeping the egg in boiling water and (3) placing the egg in cool water and then boiling it for a set amount of time. Try to determine the best, shortest, and most consistent way to soft-boil an egg. Get ready to perfect your recipe!


Figure 1. Delicious and nutritious eggs.

Terms and Concepts

  • Calorie
  • Nutrient
  • Protein
  • Vitamin
  • Mineral
  • Viscous

Questions

  • How many different grades of eggs are there? How are they sorted?
  • What is the anatomy of an egg?
  • How does applying heat to a raw egg change it from being raw to being cooked?

Bibliography

This website has great information on a variety of egg-related topics:

News Feed on This Topic

Note: A computerized matching algorithm suggests the above articles. It's not as smart as you are, and it may occasionally give humorous, ridiculous, or even annoying results! Learn more about the News Feed

 

, ,

Materials and Equipment

  • Pot, 3-quart with lid, should be large enough to hold at least one egg submerged in water
  • Eggs (3 dozen), choose one grade and size to use for the entire project.
  • Water
  • Stove top
  • Slotted spoon
  • Digital timer
  • Bowl, glass
  • Ice cubes
  • Disposable bowls (2 packages)
  • Ruler with millimeter divisions
  • Camera
  • Lab notebook

Remember Your Display Board Supplies

Remember Your Display Board Supplies

Experimental Procedure

Important Notes Before You Begin

  1. If your eggs are in the refrigerator, take them out and bring them to room temperature before you begin any testing.
    1. This may take about an hour.
  2. There is a chance that eggs can carry a bacteria called Salmonella. Salmonella can cause severe food poisoning. The Centers for Disease Control and Prevention (CDC) recommend avoiding eating eggs unless the whites and yolks are both firmly cooked. For this reason, we do not recommend eating the soft-boiled eggs in this science project; just make observations. If you would like to eat them, consider doing your science project with pasteurized eggs.
  3. When asked to make observations about your results, use your senses. You may want to make a data table in your lab notebook to record your observations and answer the following questions:
    1. Examine the egg white. Is it firm or watery? Measure the thickness of the solid white with a ruler.
      1. When you peel the egg, depending on how the egg was cooked the solid white may be along the inside of the shell or still attached to the yolk.
      2. If the thickness of the solid white seems to vary around the egg, try to measure the thinnest and thickest areas and record that range.
    2. Examine the yolk. Try poking your finger into it. Does it feel slimy (raw), viscous (thickened and sticky), or hard (cooked solid)? What color is it? Is it pale yellow or bright yellow?
    3. Overall, does it seem like the egg is soft-boiled? If not, does it seem undercooked or overcooked?
  4. Remember to always wash your hands with soap and warm water after handling eggs that are not cooked.

Cooking Method 1: Cooking the Egg in Boiling Water

  1. In your lab notebook, record the cooking method you are using.
  2. To first get the correct amount of water in the pot, place an egg in the pot and add water. Make sure that the egg is covered with about 1 inch of water. Remove the egg.
  3. Place the pot of water on the stove top, cover, and bring it to a boil. Keep an eye on the pot so you know when the water starts to boil. Heat the pot until the water is bubbling vigorously. In your lab notebook, record the stove top setting and the time required for the water to boil.
  4. Using the slotted spoon, carefully lower an egg into the boiling water. Carefully remove the slotted spoon. You want to make sure that the shell does not crack. If the shell does crack, you will have to start again.
  5. Set the digital timer for 2 minutes and boil the egg for 2 minutes. Keep the lid on the pot while the egg boils.
  6. While the egg is boiling, place a few cubes of ice in the glass bowl and fill it with enough water that it will cover the egg. This is an ice-water bath.
    1. Putting the egg in the ice-water bath will stop the egg from cooking more.
  7. Once 2 minutes have elapsed, carefully remove the egg with the slotted spoon and carefully transfer it to the ice-water bath, letting it soak for 1 minute. Turn off the stove.
  8. After 1 minute has elapsed, take the egg out of the water bath and peel it. Place the peeled egg in a disposable bowl. Evaluate the egg based on the information in the Important Notes section at the beginning of the Experimental Procedure. Record your observations in your lab notebook, along with the amount of time that the egg was cooked. Take pictures of your results and keep them in your lab notebook.
  9. Repeat steps 1–8 two more times. Each time, making sure that you use approximately the same amount of water and the same heat setting on the stove top. Also use a new disposable bowl for each egg.
  10. Repeat steps 1–9, but increase the cooking time by 2 minutes for a total of 4 minutes.
  11. Repeat steps 1–9 again, but increase the cooking time by 2 more minutes for a total of 6 minutes of cooking time.

Cooking Method 2: Steeping the Egg in Boiling Water

  1. In your lab notebook, record the cooking method you are using.
  2. To first get the correct amount of water in the pot, place an egg in the pot and add water. Make sure that the egg is covered with about 1 inch of water. Remove the egg.
  3. Place the pot of water on the stove top, cover, and bring it to a boil. Keep an eye on the pot so you know when the water starts to boil. Heat the pot until the water is bubbling vigorously. In your lab notebook, record the stove top setting and the time required for the water to boil.
  4. Using the slotted spoon, carefully lower an egg into the boiling water. Carefully remove the slotted spoon. You want to make sure that the shell does not crack. If the shell does crack, you will have to start again. Once the egg is submerged, turn off the stove and move the pot to a cool burner.
  5. Set the timer for 2 minutes and steep the egg in the just-boiled water for 2 minutes. Leave the lid off the pot while the egg steeps.
  6. While the egg is steeping, place a few ice cubes in the glass bowl and fill it with enough water that it will cover the egg.
  7. After 2 minutes have elapsed, carefully remove the egg from the pot with the slotted spoon and place it into the ice water bath. Let the egg sit in the ice-water bath for 1 minute.
  8. After 1 minute has elapsed, remove the egg from the ice-water bath and peel the egg. Place the peeled egg in a disposable bowl. Evaluate the egg based on the information in the Important Notes section at the beginning of the Experimental Procedure. Record your observations in your lab notebook, along with the amount of time that the egg was cooked. Take pictures of your results and keep them in your lab notebook.
  9. Repeat steps 1–8 two more times. Each time, making sure that you use approximately the same amount of water and the same heat setting on the stove top.
  10. Repeat steps 1–9, but increase the steeping time by 2 minutes for a total of 4 minutes.
  11. Repeat steps 1–9 again, but increase the steeping time by 2 minutes for a total of 6 minutes of steeping time.

Cooking Method 3: Bringing the Egg and Water Up to a Boil Together

  1. In your lab notebook, record the cooking method you are using.
  2. To first get the correct amount of water in the pot, place an egg in the pot and add water. Make sure that the egg is covered with about 1 inch of water. This time, do not remove the egg.
  3. Place the pot of water and the egg on the stove top, cover, and bring it to a boil. Keep an eye on the pot so you know when the water starts to boil. Let the water start to bubble vigorously. In your lab notebook, record the stove top setting and the time required for the water to boil.
  4. Once the water is vigorously boiling, set the timer for 2 minutes and boil the egg for 2 minutes. Keep the lid on the pot while the egg boils.
  5. While the egg is boiling, place a few ice cubes in the glass bowl and fill it with enough water that it will cover the egg.
  6. After 2 minutes have elapsed, carefully remove the egg from the pot with the slotted spoon and place it into the ice-water bath. Let the egg sit in the ice-water bath for 1 minute.
  7. After 1 minute has elapsed, remove the egg from the ice-water bath and peel the egg. Place the peeled egg in a disposable bowl. Evaluate the egg based on the information in the Important Notes section at the beginning of the Experimental Procedure. Record your observations in your lab notebook, along with the amount of time that the egg was cooked. Take pictures of your results and keep them in your lab notebook.
  8. Repeat steps 1–7 two more times. Each time, making sure that you use approximately the same amount of water and the same heat setting on the stove top.
  9. Repeat steps 1–8, but increase the boiling time by 2 minutes, for a total of 4 minutes.
  10. Repeat steps 1–8 again, but increase the boiling time by 2 minutes for a total of 6 minutes of boiling time.

Analyzing Your Data

  1. Compare the observations and pictures from the three sections above. Is there a recipe that consistently produces the best soft-boiled egg results? If you have results that are similar, you can evaluate which recipe is the better one. Do either of the recipes use less energy than the others?

Figure 2. Eggs cooked using the three different methods in the Experimental Procedure.

Communicating Your Results: Start Planning Your Display Board

Create an award-winning display board with tips and design ideas from the experts at ArtSkills.



Variations

  • Use an infrared thermometer, which can be purchased online, to measure the temperature of the egg white and yolk after boiling. Record the data in your lab notebook. How hot do the eggs get when using the different cooking methods?
  • Does the time to soft-boil an egg depend on the size of the egg? Pick three different sizes of eggs and start experimenting.
  • Does freshness of the egg affect the time it takes to soft-boil it? Get fresh eggs and try this experiment on some of the eggs right after obtaining them, and then try it again after you have let some of the same batch of eggs sit in the refrigerator for a few weeks. Is there a difference?
  • Eggs are often soft-boiled in water that is not quite boiling, but is instead simmering. You could try this experiment again but this time use simmering water instead of vigorously boiling water. How does this affect how well the eggs are cooked? Can you perfect your soft-boiled egg recipe even more?

Share your story with Science Buddies!

Yes,I Did This Project! Please log in (or create a free account) to let us know how things went.

Ask an Expert

The Ask an Expert Forum is intended to be a place where students can go to find answers to science questions that they have been unable to find using other resources. If you have specific questions about your science fair project or science fair, our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.

Ask an Expert

Related Links

If you like this project, you might enjoy exploring these related careers:

Food Scientist or Technologist

There is a fraction of the world's population that doesn't have enough to eat or doesn't have access to food that is nutritionally rich. Food scientists or technologists work to find new sources of food that have the right nutrition levels and that are safe for human consumption. In fact, our nation's food supply depends on food scientists and technologists that test and develop foods that meet and exceed government food safety standards. If you are interested in combining biology, chemistry, and the knowledge that you are helping people, then a career as a food scientist or technologist could be a great choice for you! Read more

Materials Scientist and Engineer

What makes it possible to create high-technology objects like computers and sports gear? It's the materials inside those products. Materials scientists and engineers develop materials, like metals, ceramics, polymers, and composites, that other engineers need for their designs. Materials scientists and engineers think atomically (meaning they understand things at the nanoscale level), but they design microscopically (at the level of a microscope), and their materials are used macroscopically (at the level the eye can see). From heat shields in space, prosthetic limbs, semiconductors, and sunscreens to snowboards, race cars, hard drives, and baking dishes, materials scientists and engineers make the materials that make life better. Read more

Food Science Technician

Good taste, texture, quality, and safety are all very important in the food industry. Food science technicians test and catalog the physical and chemical properties of food to help ensure these aspects. Read more

News Feed on This Topic

Note: A computerized matching algorithm suggests the above articles. It's not as smart as you are, and it may occasionally give humorous, ridiculous, or even annoying results! Learn more about the News Feed

 

, ,

Looking for more science fun?

Try one of our science activities for quick, anytime science explorations. The perfect thing to liven up a rainy day, school vacation, or moment of boredom.

Find an Activity

Thank you for your feedback!

One thought on “Hard Boiled Eggs How To Know When Done With Your Homework

Leave a comment

L'indirizzo email non verrà pubblicato. I campi obbligatori sono contrassegnati *