Berry Soufflé — a hot French soufflé made with fruit purée

i. Origin & history

The soufflé is a French invention, and its name is simply the past participle of souffler, "to blow" or "to puff up". Dishes of whipped egg whites baked until risen appear in French cookery from the early eighteenth century, and the soufflé became a showpiece of grand French cuisine in the nineteenth, when chefs such as Antonin Carême refined both the recipes and the ovens needed to bake them reliably. For a long time it was a dish of aristocratic and restaurant kitchens, because it demanded steady heat and a cook who could time it to the second.

Sweet soufflés fall into two broad families. The first, and best known, uses a base of crème pâtissière or a flour-thickened milk panade, flavoured with vanilla, chocolate, liqueur or coffee, into which beaten whites are folded. The second — the soufflé aux fruits — replaces the custard with a reduced fruit purée or a fruit syrup cooked to a specific temperature. Raspberry, strawberry, passion fruit and apricot are classic choices, and red-berry soufflés became a staple of French restaurant dessert menus in the twentieth century.

The fruit soufflé is also the source of a long-standing kitchen rivalry with the Grand Marnier soufflé, the other restaurant classic. Where Grand Marnier is rich, buttery and boozy, a berry soufflé is all acidity and perfume, and it is often served with a cold sauce or sorbet poured into the middle at the table.

Today it is as much a home dessert as a restaurant one. Fruit purée soufflés are forgiving to make ahead, because the base can be prepared hours in advance and even the filled ramekins can wait in the fridge for a short time before baking.

ii. What makes a fruit soufflé rise — and stay up

A soufflé rises for two reasons. Whipped egg whites trap millions of tiny air bubbles inside a network of stretched proteins; in the oven, that air expands and water in the mixture turns to steam, inflating the bubbles further. At the same time, the heat sets the egg proteins around the bubbles, fixing the structure in its risen state. The soufflé is ready at the moment the outside has set enough to hold its shape while the centre is still soft and creamy.

In a fruit soufflé, the purée does the work that custard does elsewhere: it carries flavour and gives the whites something to cling to. It must be thick and concentrated. A thin, watery purée deflates the whites and produces a soufflé that rises then weeps a puddle of pink liquid at the bottom. Cooking the sieved purée with sugar and a little cornflour until it is as thick as jam removes excess water and gives it enough body to support the foam.

The whites should be whipped to firm but glossy peaks with sugar added gradually. Sugar stabilises the foam and makes it more elastic, so it stretches rather than tears as it expands. Over-whipped whites look dry and grainy, break into lumps when folded, and produce a coarse soufflé that can crack and collapse. A little lemon juice or cream of tartar adds stability, which is particularly helpful with acidic berries.

The buttered and sugared ramekin is not decoration. The sugar crystals give the rising mixture something to grip as it climbs the sides, while the butter lets it slide upwards cleanly. Running a thumb around the inside rim before baking creates a shallow groove that helps the soufflé rise straight, giving the classic "top hat" look.

iii. Ingredients

Makes 6 servings · scroll the side panel to adjust

• 400 g raspberries or mixed berries, fresh or frozen
• 70 g caster sugar, for the purée
• 1 tbsp cornflour (cornstarch)
• 1 tbsp lemon juice
• 5 egg whites, at room temperature
• 60 g caster sugar, for the whites
• 1 pinch salt
• 20 g soft unsalted butter, for the ramekins
• 2 tbsp caster sugar, for the ramekins
• 1 tbsp icing sugar, to dust

Raspberries give the most intense flavour and colour and are the classic choice; a mix of raspberries, blackberries and strawberries works well, and blueberries are best mixed with something sharper. Frozen berries are ideal here because they are going to be puréed — thaw them first. Sieving out the seeds is worth the effort for a smooth texture. Cornflour thickens the purée without the floury taste of wheat flour, and makes the soufflé naturally gluten-free. Use egg whites that are completely free of yolk and a bowl free of any grease; even a trace of fat stops the whites foaming properly. The leftover yolks can go into a zabaione or crème anglaise to serve alongside.

iv. Method

1. Brush six 200 ml ramekins with soft butter using upward strokes from base to rim, then coat with sugar, tipping out the excess. Chill them while you make the base.
2. Purée the berries and press through a fine sieve to remove the seeds; you should have about 300 g of purée. In a small pan, whisk the purée with 70 g sugar, the cornflour and lemon juice.
3. Bring to the boil over a medium heat, stirring constantly, and cook for 2–3 minutes until thick and glossy, like soft jam. Transfer to a large bowl and cool until just warm.
4. Heat the oven to 190 °C (375 °F), fan 170 °C, with a baking tray on the middle shelf.
5. Whisk the egg whites with the salt to soft peaks. Add 60 g sugar a spoonful at a time, whisking until the whites are glossy and hold a firm peak that curls slightly at the tip.
6. Stir a quarter of the whites into the berry base to loosen it, then fold in the rest in two additions with a large metal spoon or spatula, cutting down through the middle and turning the bowl, until just combined with no large white streaks.
7. Fill the ramekins to the brim and level the tops with a palette knife. Run your thumb around the inside edge to make a small groove.
8. Place on the hot tray and bake for 12–14 minutes, until risen 3–4 cm above the rim, lightly golden on top and with a slight wobble in the centre when the tray is moved. Do not open the oven for the first 10 minutes.
9. Dust with icing sugar and serve immediately.

v. Tips & common mistakes

• Reduce the purée properly. If it is still loose and runny, it will deflate the whites and leave a pool of liquid at the bottom of each ramekin. It should hold a trail when the spoon is drawn through it.
• Do not over-whip the whites. Stop at firm, glossy peaks. Dry, cotton-wool whites are hard to fold, leave lumps and make the soufflé crack.
• Butter the ramekins with upward strokes. The vertical lines guide the soufflé straight up. Patchy coverage makes it catch and rise lopsided.
• Bake on a preheated tray. Heat from below starts the rise immediately and helps the base set, so the soufflé climbs evenly.
• Keep the oven door shut. A sudden drop in temperature in the first ten minutes can collapse a soufflé that has not yet set.
• Have everyone seated before baking. A soufflé starts to sink within a couple of minutes of leaving the oven. The dessert waits for nobody.

vi. Variations

Swap the berries for other strongly flavoured fruit: passion fruit (sieved pulp, no cooking needed beyond thickening), mango, apricot or blackcurrant all make excellent soufflés. A splash of framboise or crème de cassis in the base intensifies the flavour. Some cooks drop a few whole raspberries or a teaspoon of jam into each ramekin before filling, which makes a hidden layer of sauce.

The other branch of the family uses a custard base: try the coffee soufflé for that style. If you want the same airy berry flavour without the timing, a cold fruit mousse or a British blackberry fool are the obvious alternatives, and the Danish rødgrød med fløde shows what Scandinavia does with a red-berry purée.

vii. Serving & storage

Serve berry soufflé straight from the oven on a small plate with a napkin under the ramekin. At the table, break open the top with a spoon and pour in a little cold crème anglaise, pouring cream or berry coulis, or drop in a small scoop of vanilla ice cream or raspberry sorbet; the contrast of hot and cold is the classic way to eat it.

A baked soufflé cannot be stored. It will collapse within minutes, although the fallen soufflé still tastes good. What you can do is prepare ahead: the berry base keeps covered in the fridge for up to 2 days (warm it slightly before folding), and the ramekins can be buttered and sugared a day in advance. Filled, unbaked soufflés can wait in the fridge for up to 30 minutes before going into the oven; add a minute to the baking time.

ix. More from French

• Coffee Soufflé — custard-based soufflé
• Orange Mousse — chilled citrus mousse
• White Chocolate Mousse — silky and pale
• Raspberry Sorbet — intense berry ice
• Blackberry Fool — British fruit and cream
• Rødgrød med Fløde — Danish berry pudding