A lovely friend made this drink for me. I was amazed at how frothy the mixture was when it came out of the blender! If you wanted it to be less sweet just half fill your glass with the mixture and top with soda water.
One entire tray of ice (approx 12 cubes)
500 mls ruby red grapefruit juice
500 mls pineapple juice
1/3 jar of passionfruit syrup (in the baking section of the supermarket, strain to remove the black seeds)
Put all the ingredients in a blender or food processor and whizz up – for a long time! All the ice needs to be blitzed into frothy goodness. Pour into martini glasses. The colour will come after a minute or two once the froth settles.