Actually very easy

Meringue

The beliefMeringue is assumed to need a copper bowl and not one speck of yolk.

The truthYolk fat really does spoil the foam; copper is not needed. A pinch of citric acid or a few drops of lemon juice do the copper’s job.

2 hours

How to make it

What you need

4 egg whites (about 120 g), at room temperature
240 g caster sugar (twice the weight of the whites)
A pinch of citric acid or half a teaspoon of lemon juice
A whisk or mixer and baking paper

How the engine read this list (3 lines)

—	Egg white (from 4 eggs)	no record
240 g	Caster sugar	sugar
0 g	Citric acid	citric-acid

An empty weight means that line could not be turned into grams — either the amount is open ("to taste") or the ingredient has no record here. Neither enters the sum as zero; they do not enter it at all.

Heat the oven to 100 °C. Wipe the bowl and whisk with lemon juice and dry them: no trace of fat should remain.
Put the whites and sugar in a heatproof bowl over a pan of simmering water. Stir constantly until it reaches 71 °C; you should feel no grains of sugar between your fingers.
Take the bowl off, add the citric acid and whisk on high for 6–8 minutes, until the mixture is glossy, stands in stiff peaks and the bowl has cooled to lukewarm.
Spoon or pipe it onto baking paper in 5 cm rounds.
Dry them at 100 °C for an hour and a half. Turn the oven off and let them cool inside with the door ajar.

Why it works

Egg white is 90% water and 10% protein. When it is whisked the proteins unfold at the surface of the air bubbles, their water-loving ends turning to the liquid and their water-shy ends to the air, and they bind to each other into a thin film. Fat is that film’s worst enemy: one drop from the yolk stops the proteins settling on the air side and visibly shrinks the foam. Acid strengthens the film; citric acid or lemon juice stops the proteins over-bonding and drying the foam out. A copper bowl does the same thing: copper ions bind to ovotransferrin and keep it in balance. Sugar makes the foam stable but must come late; added before the white has at least doubled, it slows the proteins unfolding. In a Swiss meringue the white and sugar are warmed over a water bath to 71 °C: the sugar dissolves completely and the foam is firmer. For vulnerable groups this warming alone is not counted as enough: use pasteurised white.

The rough sum

240 grams going in

929 kcal in total

100% of the mass has figures behind it. This is the sum of what GOES IN rather than of what comes out. Wherever something evaporates, drains or ferments the two differ: a kilo of milk is 150 g of cheese.

Diets it qualifies for

Gluten-free Vegan Vegetarian Lactose-free

Storage & shelf life

How long it keeps

Airtight tin, room temperature: 2 weeks
Fridge: Not advised: it draws damp and turns sticky
Left out on a humid day: A few hours

The enemy of a dry meringue is damp. Sugar loves water and draws it out of the air, so a crisp meringue goes tacky within hours in a humid kitchen. Tin it airtight once it is completely cool and keep it out of the fridge.

When to bin it Soft and sticky is not spoiled: dry it again for fifteen minutes in a 100 °C oven. Mould or a sour smell: throw it out.

History

Where it comes from

The earliest known written recipes for meringue are from the early seventeenth century, in England and France. The story that it is named after Meiringen in Switzerland is widespread and has no document behind it. It grew famous with eighteenth-century French pastry — Marie Antoinette is said to have made it with her own hands. It reached Turkish cooking with the French patisseries that opened in Istanbul in the nineteenth century, and the Turkish name “beze” comes from the French “baiser”, a kiss.

The knack

In the classic French method the white is never warmed, and even a 100 °C oven may not bring the middle to 71 °C. For young children, pregnant people, older adults and anyone with a weakened immune system, use pasteurised egg white.
If a meringue weeps beads of syrup, the sugar had not fully dissolved: stir it a little longer over the water bath.
The leftover yolks keep two days in the fridge for mayonnaise or pastry cream.

The pantry