Remove the guinep skin and place the fruit into a medium bowl; set aside. In a medium pot bring water to a boil then pour over guinep and leave for 20 minutes or until cool.

Make sure your hands are very clean and use them to rub the pulp from the seeds. Massage all the fruit to get the flesh released into the water to let loose the guinep's juices.

Strain the mixture and add the lime juice. Sweeten to your taste.