How to bake the perfect swiss roll
This much-loved, very British cake may not be as hard to master as it looks. But what’s the secret to a featherlight sponge, and how can you achieve that perfect spiral of jam? How do you make a swiss roll? Push him down a mountain. Sorry, it had to be done. Thankfully, however, there are easier ways to score a slice of this much loved and, despite the name, very British cake. Neglected in recent years in favour of flashier rivals, it’s one of those rare pieces of patisserie to combine both style, in the form of that joyous spiral of jam, and substance – though not too much: it’s a sponge, not a roly poly.Thankfully, for something that looks so impressive, the swiss roll is surprisingly simple to master, but, as with so many such recipes, appropriately Swiss-style precision is the key to success. So what’s the secret to a featherlight sponge, and that perfect spiral of jam?The flourA soft sponge demands a low-gluten flour, which is why US recipes tend to cut plain flour with corn flour or some other lower-protein variety, American wheat being naturally higher in protein than the European sort. British versions occasionally flirt with the same idea in pursuit of a more velvety result. The Fortnum & Mason formula uses almost equal parts plain and potato flour (which is, apparently, popular in Scandinavian roll cakes), and Jane Hornby’s book What to Bake and How to Bake It adds a little cornflour instead. The Fortnum’s recipe in particular is so soft it’s like biting down on a cloud (reminding me fondly of a bright green roll cake I once had in the Far East) but testers prefer the flavour of the all-wheat versions. British flour tends to be fairly soft in any case, but if you are after something very delicate, seek out the stuff marked as sponge or cake flour, which will have especially low levels of gluten.