Making the basic sauce
The consistency of the panade, the basic sauce, is crucial. It must be soft enough so that the whisked eggwhites can be folded easily into it. If it is too thick, the soufflé will not rise properly. If it is too thin, it will knock air out of the whisked eggwhites and again the soufflé will not rise properly.
Making the basic sauce ahead
The panade, or basic sauce, of the soufflé can be made in advance and kept in the refrigerator for several hours before using. It should then be reheated gently before folding in the whisked eggwhites. (If the whisked eggwhites are folded into a cold base, the volume of the soufflé will be lost, as the sauce will be much stiffer and it will be difficult to fold the whites in lightly.) Once the eggwhites have been folded in, the soufflé must be baked immediately.
Under- or over-whisking the eggwhites will also result in a poorly risen soufflé. Follow the recipe instructions carefully to avoid both under- and over-whisking.
Preparing the souffle dish
A soufflé dish should always be buttered and lightly dusted (floured) before the mixture is poured in. The combination of grease and dusting – with flour, caster sugar, finely grated cheese or very fine breadcrumbs – provides the right surface for the soufflé to cling to as it rises in the dish.
Keep the oven door closed
Opening the oven door is unlikely to be a disaster unless your kitchen is very draughty, but you are much more likely to make a successful soufflé if you keep the oven door closed during cooking. The soufflé should increase in volume by at least half and sometimes as much as double, and to do this it must cook at the correct temperature. Opening the oven door will cause a sudden drop in temperature.
Using a collar
When a souffle recipe calls for the dish to have a collar, this means a piece of greaseproof or baking (parchment) paper that lines the dish and stands at least 2.5 cm above the rim. This enables the mixture to rise spectacularly without overflowing. A hot soufflé may be baked without a collar, but as the mixture is delicate, it could rise unevenly or with a crown in the centre. This does not affect the flavour.
Prevent your souffle from burning
Baking in too hot an oven will result in a creamy-centred soufflé that is well risen but burnt on the outside. Check first with an oven thermometer if your oven settings are above normal; if so, choose a slightly lower setting.
Testing for doneness
To test how well a soufflé is cooked, open the door a little and give the dish a sharp nudge. If the soufflé is very steady, it will be dry in the centre; if it trembles a little, it will have a slightly set centre; in either case it is done. If it wobbles easily, the soufflé will still be liquid in the centre and you should leave it in the oven for a few minutes longer.
Serve at once
Soufflés must be served at once, as they begin to deflate as soon as they come out of the oven.