Pour the vinegar into 1 1/2 liters of water, bring to the boil and simmer gently on a low flame. Open the eggs in a ladle and carefully slide one after the other into the vinegar water (the eggs should not touch!). Let it steep for 3 minutes. Lift out of the water with a slotted spoon and let drip off briefly on a cloth. Carefully cut off frayed edges with scissors.
The eggs can be kept warm in a little warm salt water.