They're easy, but you can still make mistakes. Here's how to make perfect hard-boiled eggs every time.
How to Make Hard Boiled Eggs in the Oven

Hard-boiled eggs are an easy snack, a good source of protien, and delicious on a salad. They're also fairly easy to make, but just like all things that are fairly easy to make, it doesn't mean they come out perfectly every time. In fact, there are some common mistakes to avoid while making hard-boiled eggs. Here's what might have tripped you up in the past and how to correct it the next time you're making a batch of boiled eggs.

Your Pot Is Too Small

You want to make sure the pot isn't terribly crowded. A pot that's too small means that the eggs might cook unevenly—any bit of an egg that's sticking out of the water isn't going to cook at the same rate as the rest of the egg. A more crowded pot also means there's more chance of the eggs cracking.

You Forgot to Add a Little Vinegar

When you bring a pot of water up to boil for eggs, it's a good idea to add a little vinegar to the water as you put the eggs in. You could put eggs and cold water into a pot, then bring it to a boil—a method that minimizes cracking. The vinegar changes the PH of the water, which encourages the egg white to stick togther. That's particularly helpful if your egg shells do crack while boiling them—the vinegar will minimize the amount of eggs that leaks out.

Your Eggs Have a Grey or Green Ring

If you've ever cracked open a hard-boiled egg to find a greenish or greyish hue on the inside, there are two reasons for that. One, you probably overcooked your eggs. Two, you probably forgot to plunge your eggs into cold water after they're done cooking. Ideally, once your eggs are cooked as much as you want, you scoop them from the pot and place them in an ice water bath. That stops them from cooking any further. You can also place the pot in your sink under running cold water to cool them down quickly.

Your Eggs Are Too Fresh

Very fresh eggs are difficult to peel once you've hard-boiled them. Save those farmer's market eggs for another dish. Slightly older eggs will give you a better result for this application.

You're Peeling Them Too Soon

If you want the egg to separate easily from the whites, you'll want to let them cool down a bit. Not only does that spare your fingers from the hot egg, it allows the egg to separate from the shell, making it easier to remove the shell.

Your Eggs Have a Flat Top

You know when you peel an egg and it turns out less than perfectly egg-shaped? That has to do, again, with the temperature differential between the egg and the water. You can use the method of adding cold eggs to cold water and bringing them to a boil, or you can also leave your eggs out of the refrigerator a bit to come closer to room temperature. That should prevent the flat top from forming—though it will taste just as delicious.