How do you get a poached egg to coagulate evenly and professionally? [duplicate]

Acidify the water with lemon or white vinegar (balsamic vinegar would be a waste to use for this, plus would stain the eggs) to facilitate protein coaugulation.

When the water is boiling, break the egg in a small dish, then create a whirpool by stirring the water just before putting the egg in. This will help to make the white coaugulate around the yolk. Gently pour the egg from the dish into the whirpool.

Also, I find using eggs at room temperature works better, so if you are storing eggs in the fridge be sure to take them out a little bit in advance.

Personally I don't like the whirlpool method as in my experience it doesn't work that well most of the time. I use a saucepan with an inverted bowl in the bottom to prevent the egg coming into contact with direct heat, but the most important factor is fresh eggs.

As eggs age, the white gets more and more watery. Thus when you put an old egg in water to poach, the majority of the white just disperses and turns to bits. In contrast, a fresh egg white is very gel-like and clings to the yolk, making it much easier to poach.

If you don't have a fresh egg but need to poach one, crack the egg into a straining spoon like this:

and let the watery part of the yolk strain away. You'll be left with the yolk and the remaining gel-like white, which will poach much better. If you end without any white, then go out and buy some fresh eggs!