If you are using the freezer compartment of the refrigerator rather than a freezer, set the refrigerator at its lowest temperature (the highest setting) 1 hour before you make the water-ice.

To make the syrup, combine the sugar and 600 ml (1 pt) water in a saucepan. Bring the mixture slowly to the boil, stirring constantly, until all the sugar has dissolved. Boil for 10 minutes and then add the lemon juice. Set aside to cool.

Pour boiling water over the nectarines and allow them to stand for 10 seconds, then skin and stone them. Rub the flesh through a fine nylon sieve until you have 300 ml (10 fl oz) puree.

Add the syrup to the puree and flavour with the strained lemon juice and almond essence to taste. Tint the mixture slightly with red food colouring if you like. Allow it to become completely cold.

Transfer the mixture to a freezer container, cover and freeze.

Stir the water-ice vigorously with a fork every 1/2 hour, until half frozen. Leave it for at least 2 or 3 hours until frozen hard.

About 1 hour before serving, transfer the water-ice from the freezer to main compartment of your refrigerator.

When you are ready to serve, scoop the nectarine water-ice into wine glasses and arrange a halved black grape on each serving.

Once the nectarines have been skinned and stoned, it is important to prepare the puree as quickly as possible without interruption as the fruit will otherwise turn brown. Regular beating is necessary to prevent large crystals forming in the ice.

If you cannot buy nectarines, fresh peaches could be used instead.