Swiss roll
A thin foam sponge that must be rolled while it is still hot and flexible, because a cooled one has set into the shape it will crack in.
Also called roll cake (INTERNATIONAL), jelly roll (US), roulade (INTERNATIONAL) — Used loosely for the same construction, and also for savoury and unbaked versions.
A Swiss roll is a whisked foam sponge baked thin in a flat tin, then rolled around a filling. Almost everything about it is governed by one fact: a baked sponge sets into whatever shape it cools in.
ROLLING IS DONE HOT FOR THAT REASON. While warm, the starch and protein structure is still soft enough to deform without fracturing. As it cools it sets, and bending a set sponge tightly breaks it. The traditional method of rolling the hot sponge with paper inside, letting it cool rolled, and then unrolling to fill is not superstition — it lets the sponge set in the shape it will finish in.
IT IS AERATED MECHANICALLY AND HAS NOTHING TO FALL BACK ON. A foam sponge contains little or no fat and usually no chemical leavener; all of its volume is air whipped into egg. Anything that knocks that air out — heavy folding, a long wait between whisking and baking, fat in the bowl — costs volume that cannot be recovered.
OVERBAKING IS THE OTHER HALF OF EVERY CRACK. A thin sponge dries very fast, and a dry sponge has lost the flexibility rolling depends on. The bake is short and the margin is small; a minute or two matters at this thickness in a way it does not in a deep cake.
What it should be like
- Structure
- Thin, flexible while warm, and set once cooled
- Crumb texture
- Fine and springy, with no fat to shorten it
- Handling
- Rolled hot; unforgiving once cool
Where it comes from
Traditional account
A long-standing account of how something originated or was done. Recorded as tradition, which is not the same as recorded as fact.
The English name attributes it to Switzerland and the attribution is not supported by anything BakeHQ has read. Rolled filled sponges are made across central Europe under several names.
More in baking history and culture.
Why a Swiss roll cracks
Three causes, and they are distinguishable.
If it cracked while being rolled for the first time and the sponge was already cool, the structure had set. Roll it hot.
If it cracked while hot, the sponge is too dry — overbaked, or baked in an oven running hotter than its dial. A correctly baked thin sponge is noticeably supple straight from the tin.
If it cracked only when it was unrolled and filled, the filling is usually the cause: too much of it, or a stiff one, forces the outside of the curve further than the sponge will stretch. A thinner layer and a softer filling both help, and neither is a compromise on the sponge itself.
Related
Part of
A whisked foam sponge — aerated mechanically and set by egg and starch.
Things that go wrong
The cake is dense and did not rise
'The egg foam was knocked out during folding' is this model’s cause and is the foam sponge’s principal failure.
A dry sponge is why a Swiss roll cracks, so the dryness model is the diagnosis behind the crack.
A thin sheet in a large flat tin exposes every hot spot.
The only product in the catalogue that is baked flat and then required to become a cylinder, which is the entire condition for this fault.
What this product needs done
Aeration
Air whipped into egg, with nothing else raising it.
Structure building
Egg protein setting into a thin flexible sheet.
Moisture retention
A sponge that has dried cannot be rolled, so retaining water is structural here rather than a matter of eating quality.
Characteristic ingredients
The entire leavening, whipped.
Dissolves readily into the foam, which coarser sugar does not.
A small quantity, folded in without knocking the air out.
Techniques involved
The whole leavening.
Where the air is most often lost.
A flat tin lined so the sheet can be lifted out hot.
Fillings, icings and creams used here
Used thin, because a filling firm enough to pipe would crack the sponge as it was rolled.
Light enough not to force the sponge open as it is rolled, and the reason the finished roll has to be eaten the same day.
Keep reading
The cake family
What every product in this family has in common, and what separates them.
Chocolate cake
Built on the same structure and handled differently — a creamed or blended cake containing cocoa solids, whose acidity and starch content change how the batter is leavened and how the crumb sets.
The cake is dense and did not rise
If it did not come out right, start from what you can see.