Vol. XVII · Eggs and Dairy Plate 3 of 10poached egg, fried egg, thick white, thin white, vinegar, fresh eggs, crispy edges, basting, 荷包蛋, sunny side upHT

Fried and Poached Eggs.

Poach a fresh egg and it sets in a neat oval; poach an old one and its thin white drifts away in wisps. Vinegar helps a little; freshness helps a lot.

A poached egg is cracked into water at about 75–85 °C, just below a simmer, and cooked until the white is set and the yolk still runny — about three to four minutes. Only the thick white holds a shape; the thin white spreads into the water as threads. Fresh eggs have more thick white (XVII.1), so freshness matters most. A splash of vinegar slightly speeds the surface setting of the white; cracking the egg into a fine sieve first to drain the thin white, and swirling the water gently, help too.

A fried egg cooks from the pan below and, unless covered or basted, barely from above. On gentle heat with butter the white sets tender and white; on high heat in plenty of oil the edges bubble, brown and crisp into lace while the yolk stays runny — the Spanish and Chinese way (荷包蛋 with crisp edges). Basting with hot fat or adding a spoon of water and a lid steams the top. The workshop poaches eggs in water of different temperatures.

Below: how set the white (average) and the yolk centre are for a large egg poached at the water temperature you choose against minutes (thermal bench, course protein rates; the egg treated as a 45 mm sphere for simplicity).

What you will learn
Workshop
Thermal bench: a large egg from 5 °C, treated as a sphere of 45 mm, in water held at the temperature chosen (h 300 W/m² K). Real poached eggs spread thinner, so they cook somewhat faster; the shape of the result, not the exact minutes, is the point.

Fresh egg, quiet water

In this model, after four minutes in 75 °C water the white is 0.16 set on average; at 90 °C, 0.38 — hotter water sets the outer white faster, but a rolling boil also tears the white apart and toughens it. Water just below a simmer, around 80–85 °C, is the compromise: the white sets in three to four minutes while the yolk stays runny.

Method for poached eggs: use the freshest eggs; crack each into a small cup (or a sieve to drain the thin white); bring a wide pan of water with a spoon of vinegar to a bare simmer; stir gently, slide the egg in, cook three to four minutes; lift out with a slotted spoon and blot. For a fried egg: tender — moderate heat, butter, lid on for a minute; crisp — hot oil, tilt the pan and spoon the oil over the white until the edges are brown lace. Eggs for the vulnerable should be cooked until the yolk is firm, or pasteurised (XVII.6).

At the stove

Poach a fresh egg and one three weeks old in the same water. Compare the shapes: the old egg's thin white wanders off in strands.

荷包蛋 means "purse egg": folded over itself as it fries, the white closes round the yolk like a small purse. In Chinese homes it is also a poached egg in sweet soup, given to guests as a sign of welcome.

Terms

Poached egg
An egg cooked out of its shell in water just below a simmer.
Thin white
The runny outer white that spreads in water.
Basting
Spooning hot fat over food to cook its top.
荷包蛋
A fried or poached egg, often folded.
Poach fresh eggs in water just below a simmer; fry gently for tender whites, hot for crisp brown lace.

Sources

  1. Egg proteins: ovotransferrin sets near 62 °C, ovalbumin near 80 °C, the yolk thickens near 65 °C and sets near 70 °C (H. McGee, On Food and Cooking, 2004, ch. 2; P. Barham, The Science of Cooking, 2001).
  2. H. McGee, On Food and Cooking: The Science and Lore of the Kitchen, 2nd ed., Scribner, 2004.