Simmering and Boiling of Eggs

Simmering. Simmering temperatures are used to prepare eggs that are hard or soft “boiled”, coddled, poached, incorporated into soft custards, or microwaved.

“Boiling”. Although the term “hard-boiled eggs” is commonly used, eggs should actually be simmered and never boiled, because they will become tough and rubbery if so treated. The high heat of boiling also transforms the iron in the egg yolk into ferrous sulfide, causing the greenish-black color and unpleasant flavor found in the yolk of overly hard-cooked eggs.

Simmering hard-cooked eggs makes them prone to cracking, but this can be avoided by first warming eggs to room temperature in a bowl of warm water. Eggs crack because the pressure created by fast-heating water pops the shell. Another way to reduce the chances of cracking is to push a sterilized pin or needle through the large end of the shell where the air cell is located. To reduce cracking still further, a spoon or other utensil may be used to place the eggs gently in the water.

There are two methods for hard-cooking eggs: hot start and cold start. Each has advantages and disadvantages; each produces acceptable products. The benefits of using the hot-start method are greater temperature control, eggs that are easier to peel, and a shorter total cooking time. A drawback is that lowering the eggs into boiling water may cause them to crack. The advantages to the cold-start method are that less attention to the process is required, the eggs are easier to add to the water, and they are less likely to break. On the other hand, starting eggs out in cold water may cause the egg white by the shell’s surface to be more rubbery, and there is a greater chance of a greenish tint forming on the egg white.

In the hot-start method, the water is heated to boiling and then the eggs are completely immersed in the boiling water. The heat is immediately reduced to simmer, and the eggs are cooked for 3 to 15 minutes, depending on the desired doneness:

• Soft (3 to 4 minutes)
• Medium (5 to 7 minutes)
• Hard (12 to 15 minutes)

The cooked eggs are drained and then rinsed under cold running water to stop further cooking from residual heat. The extreme temperature change from hot to cold also helps loosen the egg’s membrane from the shell, making it easier to peel. To further ease peeling, the first crack should be made at the air cell located at the larger end of the egg, and then the egg rolled gently between the hands to break the shell all over. Peeling under cold running water also makes the job easier. Fresher eggs are harder to peel because the air cell is smaller and the membrane is tight against the cell wall. Although the larger air cell and higher pH of older eggs makes them easier to peel, they also tend to break more easily during heating.

In the cold-start method, the eggs are placed in a saucepan with enough cold water to cover them by at least an inch. The water is brought to a boil, immediately lowered to a simmer, and the eggs are then cooked to order:

• Soft (1 minute)
• Medium (3 to 5 minutes)
• Hard (10 minutes)

Another way to prepare hard-cooked eggs from a cold start is to remove the pan from the heat as soon as the water boils, cover it tightly, and let it stand for 20 minutes. Cold-start eggs are less likely to crack during cooking. Once cooked, eggs can be cut into slices or wedges. Dipping the knife in hot water before slicing keeps the hard-cooked eggs from falling apart. One way to tell a shelled hard-cooked egg from a raw one is to spin the egg on its side. A smoothly spinning egg is hard cooked, while one that wobbles out of balance is not.