Ingredient

Swiss roll

A Swiss roll is a fatless whisked sponge — eggs and sugar beaten to a foam, flour folded in, baked fast and thin. It is flexible only while hot, which is why the rolling happens in the first minute out of the oven rather than at the end.

The whisked sponge

There is no butter and no raising agent. All the lift comes from air whisked into whole eggs with sugar, which is a slower and more fragile foam than egg white alone. Whisk until the mixture is pale, thick, and holds a ribbon on the surface for a few seconds when the whisk is lifted.

Warming the eggs and sugar over a pan of hot water first — to about blood temperature — makes the foam build faster and hold better. It is worth the extra two minutes.

Fold the sifted flour in with a large metal spoon in as few strokes as possible. Every stroke costs volume, and with no fat and no raising agent, volume is all there is.

Baking and rolling

1. Line a shallow Swiss roll tin with parchment, leaving an overhang. The sponge must come out cleanly and fast.
2. Spread the batter to an even thickness, right into the corners. Uneven thickness bakes unevenly and cracks where it is thin.
3. Bake hot and briefly — around 200°C for eight to ten minutes. It is done when it is golden and springs back; a minute too long makes it brittle.
4. Turn it out immediately onto a sheet of sugared parchment and peel off the lining paper.
5. Trim the crisp edges off with a sharp knife. Crisp edges are where cracks start.
6. Score a line about 2cm in from the short edge, cutting halfway through. This gives the first turn something to fold around.
7. Roll it up now, while hot, with the paper inside, and leave it rolled until cold. Then unroll, fill, and re-roll.

Why it cracks

• Cooled before rolling. The sponge sets rigid. It must be rolled hot.
• Overbaked. A dry sponge has no flexibility at all. Watch it closely — the window is a minute or two.
• Rolled too tightly the second time, or over-filled so the filling forces the sponge apart.
• Crisp edges left on. Trim them.
• Rolled the wrong way. Roll from the short edge for a fat roll, the long edge for a thin one — but roll along the same axis both times.
• A little cracking is normal and disappears under a dusting of icing sugar.

Fillings

Jam alone

The classic. Warm it slightly so it spreads without tearing the sponge.

Jam and cream

Whip the cream firmly, or it squeezes out. Keep the layer thin.

Buttercream

Stable and easy to slice, and the usual choice for a decorated roll.

Chocolate ganache

Makes it a bûche de Noël. Let it cool to spreadable first.

Lemon curd

Sharp against a sweet sponge, and it needs no whipping.

Common questions