Egg whites should be at room temperature as it allows them to be whisked to maximum volume. Damp or humid conditions are not ideal for meringues as the high sugar content tends to absorb moisture, so try to wait for a warm dry day before making them. A metal or glass bowl will produce the best results. The bowl should be as large as possible to allow themaximum air to be whisked In. Whisk slowly at first, then gradually increase the speed to maximum.
Although it is possible to overwhisk egg whites, the more common fault is not working them enough, so carry on until they are really stiff. Whisked egg whites for meringues should be stiffer than for most recipes. When whisked for meringue, the whites are referred to as being "dry" because they look almost dry in texture and they can be cut with a knife to leave a clean, flat surface on the foamy white.
The usual proportion of ingredients is 25-50g (2-4 tbsp) caster sugar to each egg white, Cream of tartar, salt, cornflour and/or vinegar are sometimes added. A pinch of cream of tartar or salt helps to stiffen the whites before the sugar is added. Cornflour and vinegar help to give a meringue with a slightly soft and chewy middle contrasting with a crisp outer crust.
A large balloon whisk will give excellent results when whisking meringue. This can be very hard work so it may be preferable to use an electric whisk, However, you will achieve better results if you can whisk in the sugar by hand.
To achieve crisp, white meringues, the mixture needs very slow gentle cooking. This allows the meringue to dry out, without becoming brown. Preheat the oven to 150 degrees C, bake the meringue for 10 minutes, then reduce the heat to 140 degrees C. Allow a further 30-40 minutes for individual meringues and shapes, depending on size. Larger meringues or layers for gateaux should be dried for at least 1 hour. Thick layers of meringue or a deep pavlova may take 1-2 hours. Turn off the heat and leave the cooked meringue in the cooling oven until cold and crisp.