This is not a myth; fresh eggs sink while bad eggs float to the top. Simply fill a bowl with cold tap water and place your eggs in it. If they sink to the bottom and lay flat on one side, they are fresh and good to eat. A bad egg will float because of the large air cell that forms at its base.

Saltwater is denser than fresh water because of its salt content. The egg will sink in the fresh water because it has greater density than the water. The egg will float in the salt water because when salt is added to water its density becomes greater than that of the egg. That makes the egg float.

If the egg sinks or stays at the bottom, it is still fresh. An older egg will either stand on its end or float. The float test works because air builds up inside the egg as it ages, and this increases its buoyancy. However, an egg that floats may still be safe to eat.

Why Objects Float or Sink Placing an object that’s denser than fresh water automatically sinks. In our Salt Water Egg experiment, because the egg is denser than tap water, it pushes away water particles so it can make space for itself hence the sinking motion.

The density of the average egg will be slightly greater than that of water, so it will sink. To make the egg float, we have to make the water more dense by adding salt. For 1 cup of water, adding 3 tbsp. of salt should be about enough to make the egg float.

Vinegar is an acid. If you soak an egg in vinegar the eggshell will absorb the acid and break down, or dissolve. The calcium carbonate will become carbon dioxide gas, which will go into the air.

Both experiments can be done with raw or hard-boiled eggs. Place the egg into a bowl filled with white vinegar. Allow the vinegar to cover the egg completely and let it sit, undisturbed, for 24 hours.

The little bubbles you see in the water are made of carbon dioxide gas; just like the bubbles from your vinegar and baking soda volcano. Once the shell is gone, the vinegar will cross over the semi-permeable membrane (through a process called “osmosis”) and slightly inflate the egg.

What IS true is that soda contains acid that will dissolve the enamel of teeth over time. Our experiment is simple. Take a hard boiled egg and immerse it in Pepsi or Coke for 24 hours and analyze your result. Well, I found a study that concluded that prolonged exposure to soda can lead to significant tooth enamel loss.

When you put a naked egg in corn syrup, you are creating a situation where the egg membrane separates two solutions with different concentrations of water. The egg white is about 90% water; corn syrup is about 25% water. So water migrates from inside the egg to outside the egg, leaving the egg limp and flabby.

The water test for egg freshness Fill a bowl or glass with about four inches of cold water and gently place your egg(s) inside. Very fresh eggs will sink to the bottom and lay on their sides. If an egg stays at the bottom but stands on its small end, it’s still fine to eat; just not quite as fresh.

Peeled hard boiled eggs can be stored in the refrigerator in a bowl of cold water to cover for about 1 week (change the water daily).

Eggshells Don’t Dissolve in Water.

Gently place the egg in the bottom of the glass taking care not to crack it. Pour enough vinegar (or cola) over the egg until it is completely submerged in the liquid. The chemical reaction between the acetic acid in the cola and the calcium carbonate in the eggshell causes the shell to dissolve.

Place your raw egg in a jar and cover it with vinegar. You will notice the reaction of the egg shell with calcium carbonate and vinegar. It will bubble for the first day (as above) The second day you need to change the vinegar. After 48 hours we carefully rinsed the raw egg and noticed it was transparent!

Instructions

1. Get a raw egg and carefully place it into a glass or jar.
2. Fill the glass with white vinegar until the egg is completely submerged.
3. Leave the egg in the glass for 1-3 days.
4. Remove the egg from the glass and rinse it under some tap water.
5. Examine the egg.

Carefully lower one egg into each of 4 glasses. Fill three of the glasses with vinegar and one glass with distilled water. There should be just enough liquid to cover the eggs. Add a drop or two of liquid food coloring to each glass.

1. First get permission to use kitchen equipment and eggs. Then put a raw egg (in its shell) into a bowl and cover it completely with vinegar.
2. Wait two days, then drain off the vinegar. When you touch the egg, it will feel rubbery. Be careful not to break the membrane, and wash your hands after you touch the egg.

The more water that gets cooked out of the eggs, the tighter the protein webs will be. If they get too tight like when eggs are scrambled for too long, the eggs will become tough and rubbery. On the other hand, if you don’t cook the eggs long enough, too much water will remain in the eggs so they will be runny.

When you place the egg into the vinegar, you will start to observe bubbles. These bubbles are a chemical reaction between the acid in the vinegar and the base in the calcium carbonate of the eggshell. The eggshell dissolves and leaves a soft, bendable, squeeze-able, rubber egg.

You can make a coloured bouncy egg by adding food colouring to the vinegar. Or, you can soak raw eggs in vinegar, with a similar result. Don’t bounce raw eggs though – they might pop!

one to two days

Rubber Egg Materials

1. Eggs.
2. Clear cup or jar.
3. Distilled White Vinegar.
4. Food Coloring.
5. Bowl of water.

Carefully pour the old vinegar down the drain and cover the egg with fresh vinegar. Place the glass with the vinegar and egg in a safe place for a week—that’s right, 7 days! Don’t disturb the egg but pay close attention to the bubbles forming on the surface of the shell (or what’s left of it).

After the nail polish has dried, place the egg into the measuring cup, marked side down so the Crest toothpaste covers half the egg. Make sure the egg does not touch the bottom of the cup. Cover the cup tightly with plastic wrap and leave it in a safe place at room temperature for at least four full days (96 hours).

Leave the egg in the water for 24 hours. Osmosis will occur; that is, the water will migrate from the side of the membrane where water molecules are abundant (i.e. outside the egg) to the side where water molecules are less abundant (inside the egg). After 24 hours, the egg will be plump again!

An egg floats in salt water because the mass of the salt water displaced is equal to the mass of the egg. The egg’s density is less than the density of the salt water. When an egg is placed in fresh water it immediately sinks to the bottom of the container it is placed in.

The density of a material decides whether it will sink or float. Materials denser or heavier than a liquid will sink in it, and even liquid that is denser than another will sink. For example, an egg floats in salt water because the egg is less dense than the salt water.

A concentrated sugar solution is hypertonic compared to the solution inside the egg. Therefore when the egg is placed in the concentrated sugar solution water flows out of the egg, causing it to shrivel.

In general, the fresher an egg before boiling, the more difficult it is to separate the shell cleanly from the egg white. As a fresh egg ages, it gradually loses both moisture and carbon dioxide through pores in the shell; as a consequence, the contents of the egg shrink and the pH of the albumen becomes more basic.

If you are talking about a chicken egg, then yes, a chicken egg can absorb water through the shell. By putting a warm egg into cold water, as the egg cools it will contract and draw moisture through the porous outter shell. Remember that egg shells are porous and developing chick breath through the shell.

Experiment and see. Carefully lift the flabby egg from the corn syrup and place it into a container of water. The water will migrate from the side of the membrane where water molecules are abundant (outside the egg) to the side where water molecules are less abundant. After 24 hours, the egg will be plump again.

Orange juice and vinegar both contain acids which react with the calcium carbonate in the eggs to produce carbon dioxide gas. This is why the eggs fizz in those liquids. Over time, this reaction has the effect of destroying the egg shells and leaving behind the inside of the egg.

Protein. One reason that eggs and yogurt are particularly healthful for breakfast is that this combination is high in beneficial protein. By consuming eggs and yogurt for breakfast, you can become much closer to achieving your daily protein needs.

I’ve had no problems boiling eggs in the same pot as my rice or pasta. I usually place them very gently into the boiling water.