Heat 2 to 3 inches of water in a large saucepan over a medium heat until it almost boiling. Then add the vinegar.
Crack the eggs into 4 small cups and slide each from the cup into your simmering water.
If an eggs sinks to the bottom, wait until it is nearly set before attempting to poke at it with a slotted spoon. This will ensure that the yolk does not break. Ensure that the water temperature is maintained at just below a simmer. You may need to reduce the temperature to low.
Cook the eggs until the whites are set and the centers are still soft. Remove the eggs with a large slotted spoon and set in a separate pot of water that is 150 degrees F. Cover this 2nd pot and let stand for 15 minutes; reheat if the temperature falls below 145 degrees F.
Drain the eggs with a slotted spoon and hold it against a clean paper towel to allow as much water to be absorbed as possible.
Serve the poached egg on buttered toast or English muffins or any recipe calling for a poached egg(s).