Whats Going On? Why dont I just let the eggs boil? “A boiled egg may be part of the breakfast tradition in many households, but boiling is a miserable way to treat an egg. Because high heat toughens protein, the major constituent of eggs, boiling quickly changes an egg from a tender gel to a resilient sphere. You might be surprised to learn that egg white solidifies between 140º F and 149º Ffar below waters boiling point. Egg yolk coagulates between 149º F and 158º F, a temperature higher than egg whites because the yolk's protein structure is different and not as sensitive to heat. When an egg is in boiling water, the intense heat promotes extensive protein bonding, so it solidifies quickly and changes to a texture thats best described as rubbery. Cooked gently, eggs are firm but still tender. They not only taste better, theyre easier to digest. —Anne Gardiner and Sue Wilson, The Inquisitive Cook What happens when egg white cooks? Egg-white proteins are long molecules, made up of chains of amino acids linked together. In a raw egg, these proteins are curled and folded to form a compact ball. When you cook an egg, these proteins uncurl and form new bonds with one another. The longer you heat the proteins and the higher the temperature, the tighter the proteins will bond to each other. The tightness of these bonds determines whether the eggs are cooked just rightor overcooked. Our method for hard cooking eggs heats the eggs slowly, making for loose bonds among the proteins and tender, rather than rubbery, egg whites. How can I stop the yolk from turning green? Plunging hard-cooked eggs into cold water helps keep the yolk from turning green. The green-gray color (and the whiff of sulfur smell that often accompanies it) comes from the reaction of iron in the egg yolk and sulfur in the egg white. When heated, the two can combine to make green-gray ferrous sulfide and hydrogen sulfide gas. To avoid getting a green yolk, cook your eggs just long enough to reach the desired doneness—no more. And quickly plunge the cooked eggs into cold water to stop the cooking process and minimize the iron-sulfur reaction. Some people make a pinhole in an egg before they cook it. Why? You may want to use a pin to poke a small hole in the large end of the egg before you boil it. The hole lets air escape from the air pocket at the large end of the egg, giving you a hard-cooked egg that is rounded, rather than flat, on the large end. Some say that water leaking in through this hole makes eggs easier to peel, but we havent noticed any difference in “peelability.” Why are eggs sometimes hard to peel? When an egg is very fresh, the cooked egg white may stick to the membranes inside the shell, making the egg difficult to peel. As an egg ages, the white becomes more alkaline and loosens its grip on the membrane. For the most peelable eggs, buy eggs a week to ten days before you hard cook them. To make any egg easier to peel, crack the shell all over by rolling the egg between your hands. This breaks the shell into tiny pieces. Its easier to get each tiny piece free of the white than to try to pull off a big chunk. close this window |
FAQs
The heat coming from your stove denatures the protein by disrupting some of its bonds that held the molecule into shape. In the case of hard-boiled eggs, the proteins clump together and solidify, causing the egg white and yolk to harden.
What is the chemical reaction in boiling an egg? ›
The chemical composition of a boiled egg is different from that of a raw egg. Heat causes denaturation of protein chains, converting egg into a solid mass which can not be converted back into its solid form. Therefore, it is a type of chemical change.
What causes deviled eggs to get watery? ›
While proper cooking techniques are the first step to avoiding weeping, experimenting with certain deviled egg ingredients, unfortunately, can result in a watery, sloppy appearance on the plate. Ingredients with a high water content, like tomatoes or cucumbers, can help create this wet scenario.
How are eggs cooked so that the yolk and white are firm without being rubbery? ›
Starting with cold water lets you heat the egg more slowly, which keeps the whites from getting rubbery.
What is the science behind the egg experiment? ›
The acidic vinegar leaves the membrane that lines the inside of the shell intact. Some of the vinegar permeates the membrane due to osmosis, which is why the egg swells. If you shake the egg, you can see the yolk sloshing around in the white.
What are some science facts about eggs? ›
Eggs are a complete protein. In fact, eggs are often the standard that food scientists use when they assess the protein quality of other foods. Eggs are one of the few foods rich in choline, a nutrient that helps support lifelong brain health including memory, thinking, mood and more.
What is the physics behind boiled eggs? ›
As the proteins form these new, strong bonds, the water that surrounded each protein molecule when the egg was liquid is forced out. That's why the egg turns hard. (Heat affects all of the proteins in an egg, so it's the best way to cook an egg.)
What is the chemistry behind hard-boiled eggs? ›
Heating causes the weak chemical bonds that keep these proteins entangled to break. The egg proteins then unravel and bump into other uncurled proteins, causing them to bond to one another, a process called coagulation. Water molecules are now trapped in a network of interconnected proteins.
Which type of chemical reaction is in cooking an egg? ›
Frying an egg is a chemical reaction. It is an example of an endothermic reaction or one that takes in heat to make the reaction occur. An egg is made up of proteins and water, and the yolk also contains fat. When an egg is heated, the proteins begin to change their structure.
What happens if you put too much mayo in deviled eggs? ›
Going overboard with the mayo.
But when you're heavy-handed with this ingredient, not only will it overpower the taste of the filling, but it can also make for a loose, runny filling that's tough to pipe into the egg white.
A light-colored vinegar, like the white-wine vinegar we use in these creamy deviled eggs, brings a touch of acidity to the filling and balances the richness of the yolks and the mayonnaise.
Why put paprika on deviled eggs? ›
Standard deviled eggs are undeniably good, but adding a touch of tomato paste and a generous pinch of smoked paprika makes them a bit more sophisticated. The flavor is gently sweet, forcefully spicy and perfectly smoky.
Why add salt to boil eggs? ›
Hence, this helps the water to attain a temperature higher than 100 ° C before starting to boil. This phenomenon helps cook and hard boil the egg quicker as the addition of salt has increased the boiling point of water. Also, the added salt to the water prevents an egg from cracking during cooking.
Why do deviled eggs smell like sulfur? ›
The green-gray color (and the whiff of sulfur smell that often accompanies it) comes from the reaction of iron in the egg yolk and sulfur in the egg white. When heated, the two can combine to make green-gray ferrous sulfide and hydrogen sulfide gas.
How is cooking an egg a chemical reaction? ›
When an egg is fried, the bonds in the egg proteins break and then form new bonds with other proteins. In the process, water molecules surrounding each protein molecule are forced out. This turns the egg solid. The method of heating an egg for frying is thus a chemical change because the process is not reversible.
What is the chemistry of eggs? ›
Egg Minerals
The egg yolk contains 1 % minerals, with phosphorus as the most abundant mineral component. More than 60 % of the total phosphorus in egg yolks is contained in phospholipids. The major inorganic components of egg white are sulfur, potassium, sodium, and chloride.
What is the basic principle of egg cooking explain? ›
The most important rule of egg cookery is a very simple one: avoid high temperature and long cooking times. In other words, do not overcook. Eggs are largely proteins, so the principle of coagulation is important to consider.
