Pour water and 400 grams of sugar into a saucepan.

Heat the mixture until it reaches a temperature of 121 degrees Celsius (250 degrees Fahrenheit) - here it is necessary to use a sugar thermometer. In the first couple of minutes while the sugar is heating, it is not so important to stir the saucepan constantly - only occasionally.

Meanwhile, whisk the egg whites with the remaining 100 grams of sugar using an electric mixer. Whisk until the mixture is slightly stiff.

When the sugar temperature reaches 121 degrees Celsius (250 degrees Fahrenheit), remove the saucepan from the heat. Slowly pour the sugar water (in a thin stream) into the stiffly beaten egg whites while the electric mixer is still running.

Whisk until the mixture is so stiff that you can create "peaks" in the meringue that stand firm. This can be achieved when the meringue mixture is completely cool - it takes about 10 minutes.

This type of meringue is typically used as a decoration for cakes and tarts. A classic is a French lemon tart, where the meringue is piped onto the cake in a beautiful pattern and then the surface is torched with a gas burner.