A sugar thermometer is essential for preparing this meringue. The liquid glucose prevents crystals from forming in the egg whites when the sugar syrup is added.
360g (heaped 1¾ cups) caster (superfine) sugar
30g (2 tbsp) liquid glucose (optional)
6 medium egg whites
Pour 80 ml (⅓ cup) water into a heavy-based saucepan, add the sugar and glucose if using, and set over a medium heat. Bring to the boil, stirring occasionally and brushing down any crystals that form on the side of the pan, using a pastry brush moistened with water. Increase the heat and place a sugar thermometer in the boiling syrup to register when it reaches 110°C/230ºF.
Still keeping an eye on the syrup, beat the egg whites until they hold peaks, either by hand or with an electric mixer. Stop cooking the syrup the moment it reaches 121°C/250ºF. Take the pan off the heat and let the bubbling subside for 30 seconds. Pour the syrup on to the beaten egg whites in a thin, steady stream, whisking at low speed with the mixer or by hand until very firm.
When all the syrup has been absorbed, continue to beat at low speed for 15 minutes, until the meringue is almost completely cold (30 – 35°C/86–95ºF). It is now ready to use (see overleaf).
The meringue can be kept in an airtight container in the fridge for up to 48 hours before use.
