• 125 g (4½ oz) caster (superfine) sugar
• 150 ml (5 fl oz) Sauternes (see Note)
• 2 ml (1/15 fl oz) orange blossom water
• 1 vanilla bean, split and seeds scraped
• 20 saffron threads
• finely grated zest of 1 orange

Place all the ingredients and 500 ml (17 fl oz/2 cups) water in a saucepan and bring to the boil. Set aside for 20 minutes to infuse.