Rosy Pink Grapefruit Marmalade
Put the pink grapefruits into a large saucepan, filled with enough water so that they float freely, bring to a boil and simmer for about 2 hours, until they are soft and a little puffed. Add more hot water to keep the grapefruits covered as needed. This can be done the day or night before finishing the marmalade. Refrigerate the fruits until you're ready to finish the process.
Put the fruits back into the saucepan, add the sugar and 2 tablespoons of the rose water. Let the sugar dissolve over a gentle heat and then raise the heat to bring the mixture to a boil. Allow to bubble away for 25 minutes until it has reached the setting point. Stir in the final tablespoon of rosewater. Spoon out any seeds which float to the surface.