How to boil eggs?

First, some rules should be memorized.
1) Never boil eggs that are just taken out of the fridge, because very cold eggs that are put into the hot water are likely to crack.
2) Use a timer: it is no use trying to guess how long eggs have been boiled and reminding yourself to look at the clock.
3) Never overboil eggs (if you do not have any timer), otherwise yolks will blacken and whites will look like rubber.
4) If eggs are very fresh (less than 4 days), boil them for 3 minutes longer.
5) Always use a small saucepan, for when there is too much space, eggs may bump against each other and crack.
6) Never boil to the vigorous boil; they must be boiled over a medium heat.
7) Remember that eggs have a cushion on the blunt end, where air is accumulated. While boiling, pressure can be gathered there and the shell will crack. To avoid that, pierce the egg with a needle on its blunt end, so that steam will go out.

Of course, different people like eggs cooked by different methods. We suggest the easiest method of eggs boiling, on which you can rely, regardless of the taste. 

Soft-boiled eggs, method 1 
First of all, you should pour some boiling water in a little saucepan so that the water exceeds the eggs by 1 cm. Then put the eggs one by one quickly, but carefully, with a table spoon into the water. After that turn on the timer and boil the eggs in the boiling water precisely for 1 minute. Then take the saucepan from the heat and put the lid on it, turn on the timer again and measure:
• 6 minutes to have a soft yolk with a slightly cooked, but still liquid white
• 7 minutes to have a denser yolk with a fully hard white.

Soft-boiled eggs, method 2 
Another method that works well likewise. This time eggs should be put into the saucepan, cold water is to be poured, the saucepan is to be put over a big heat and as soon as they start boiling, decrease the heat and measure:
• 3 minutes, if you want to have a semi-liquid egg 
• 4 minutes, to have a white "harden", but a yolk to remain liquid 
• 5 minutes, to have a yolk and a white boiled up, but a brightly yellow spot to remain in the core.

Hard-boiled eggs 
Put the eggs in a saucepan and pour cold water in it. Bring it to a boil, turn on the timer for 6 minutes, if you want to have the eggs slightly liquid in the core, and for 7 minutes, if you want the eggs to be fully cooked.
After that, it is very important to pour some cold water on them. Let the eggs lie in the running cold water for 1 minute, then leave them in the cold water for about 2 minutes, until they cool down, so that you can take  them in your hands.
Underboiled 
If you cut up an underboiled egg, the yolk will be liquid and the color will be dark-golden instead of light yellow.
Perfectly  boiled 
The boiled egg’s white must be tender, and its yolk must be crumbly, but dense.

Overboiled 
The white of the overboiled egg becomes "like rubber" to the taste; an unpleasant greenish- gray tint (though harmless) appears on the yolk.
Cleaning up of hard-boiled eggs
It also turns out to be not easy to clean up the boiled eggs, if the eggs are too fresh. That’s why there are some rules: Rule No. 1: boil the eggs at least 5 days after the date of their packaging. It is easier to clean them up by cracking first the shell all over the egg, and then keep it under the running water, starting from the blunt end. The water will wash away all little pieces of the shell. Then the eggs should be put again into the cold water, until they fully cool up. If you do not cool up the eggs quickly, they will continue cooking and they will be overboiled and then the problem of a blackened yolk will appear.