When my former husband and I opened a boarding school many years ago, I found myself confounded by the simple process of scrambling eggs. I was a novice cook then, and I thought eggs were something any beginner should be able to cook. I was wrong. Most mornings I ended up with a skillet full of tough curds that stuck like crazy. It turns out that many experienced cooks, too, can be frustrated by this basic food that’s easy to mess up. While it took my German mother-in-law to show me how to do it right, you can solve many of your egg problems simply by knowing how eggs cook.

To understand why eggs overcook so easily, it helps to understand how proteins behave when they’re heated.Proteins are shaped like small coils. When gently heated, they unwind (denature) and join together loosely with neighboring denatured proteins. Water between or attached to the proteins is held in a moist, tender network. If the heat is too high or the cooking time too long, the protein mesh tightens, squeezing out the water and making the proteins tough, leathery, and watery. So make gentle cooking a rule no matter how you prepare your eggs.

The trick to “hard-boiled” eggs:The trick to making hard-boiled eggs is actually not to boil them at all. Watch the video to learn how tomake perfect hard-cooked eggs.

Watch the time with hard-cooked eggs

Since eggs shouldn’t be cooked at a hard boil, egg experts prefer the term “hard-cooked” over “hard-boiled.” Whatever you call them, there are two problems you’ll want to avoid: cracked shells and the ugly green layer that can form around the yolk. For perfect cooking, start with eggs that don’t have any visible cracks. If they’ve been refrigerated, warm the eggs for four to five minutes in hot tap water. By bringing them to room temperature, they’re much less likely to crack in the hot water. In case small cracks do develop, add salt to the cooking water. The salt will help to speed up the denaturing of the egg white, causing less of it to feather into the water. Use at least a tablespoon of table salt per two quarts of water.

When hard-cooking eggs, watch the time carefully. Overcooking causes a green layer to form around the yolk. This layer is caused by a reaction between the iron in the yolk and the sulfur in the white. Heat speeds up this reaction, so the longer your eggs cook, the greater the chance of discoloration. I arrange my eggs in one layer and add cold water to cover them by an inch and a half. I partially cover the pot, and when the water has reached a full rolling boil, I turn the heat down to low, completely cover the pan, and let the eggs cook for thirty seconds. Then I remove them from the heat and let them sit in the hot water for fifteen minutes. I then put them in a bowl of heavily iced water for five minutes to further prevent overcooking.

Older eggs are easier to peel. The higher pH of an older egg makes the shell come off easier. That’s why I don’t recommend, as some cooks do, adding vinegar to the cooking water, since it would reduce the natural alkalinity of the slightly older eggs.

What to do with hard-cooked eggs?If you’ve got hard-cooked eggs from Easter or you’re looking for more ways to incorporate hard-cooked eggs into your meals,view the slideshow Hard-Cooked, Super Easyfor recipe ideas.

Fresh eggs are best for poaching

一个荷包蛋将团结和tender, not tough. But improperly cooked, a poached egg can be a cloudy mess of feathered egg whites. The first trick to poaching eggs is to use fresh eggs. The thicker white of a fresh egg poaches beautifully without creating all that mess in the water. Getting the egg to set quickly is also important when poaching. Both acid and salt make proteins in an egg denature faster, so add a little vinegar or salt (or both) to the cooking water. For up to four eggs, I like to use a large, nonstick skillet filled a little over halfway with water.

When the water reaches a slow boil, break your egg into a saucer and then slip it into the water. This initial dunk will set the outside and keep it from spreading. Once the water returns to a boil, reduce the heat to a low simmer. By simmering the eggs rather than boiling them, you provide gentle cooking that results in a tender egg. When the white is firm, your egg is done.

A warm pan keeps scrambled eggs from sticking

Scrambled eggs are a breakfast classic, but more often than not, you can find half of them irretrievably plastered to the bottom of the pan. And as with the other methods of preparing eggs, it’s easy to overcook scrambled eggs.

Avoid the temptation to pour raw eggs into a cold pan. This allows them to get into any nicks or imperfections in the surface, causing you to literally cook the eggs into the pan. Heating the empty pan first will expand the metal and effectively “seal” those imperfections so your eggs will cook on the surface, not below it. Your pan is hot enough when you can feel the heat on the upper edge of the pan. I gently heat a heavy, nonstick skillet, remove it from the heat, and spray it lightly with a nonstick cooking spray. Then I return it to medium or low heat for a few seconds before adding the eggs. Don’t leave the sprayed empty pan over direct heat for too long, as the spray can “cook” onto the pan, leaving a residue that’s hard to remove. You can use butter instead of the spray, but be sure to keep the heat low, because butter can burn and cause sticking, too.

After you add the beaten eggs to the pan, let them sit untouched for a full minute and they will puff magnificently. The egg holds on to trapped air, which expands when heated. If you stir the eggs vigorously immediately after they go into the pan, you’ll stir all the air out of the egg and end up with small curds and not much volume.

After the eggs have puffed, gently push one edge to the center to allow the uncooked eggs to flow into the bare pan. Do this until no liquid eggs flow to the edge and you have a pan of soft mounds that still look moist. Eggs continue to cook after you remove them from the heat, so it’s important to remove them when they aren’t quite done. By following these tips, you’ll have soft, fluffy eggs, not tough, watery ones.