Granadilla jam

Halve the granadillas, remove the pulp and set it aside. Place the skins in a large saucepan (not aluminium) and add the
water and lemon juice. Cover with the lid and boil the skins over a medium heat until the inner skin turns dark red and is soft enough to scrape out with a teaspoon (approximately 40 minutes. Drain the liquid and set it aside.
Scrape out the red pulp from the skins and process in a food processor. Throw the outer skins away and measure the quantity of processed pulp (you will nee approximately 250g white sugar for every 250ml of pulp. Add the reserved cooking liquid to the pulp and sugar in a saucepan. Slowly heat the mixture to boiling point and stir continuously until all the sugar has been dissolved, then cook the jam uncovered for approximately 1½-2 hours over a low heat,do not stir for the first hour.
At the beginning skim off the foam that forms on top and after one hour stir occasionally until the jam begins to thicken. Test if the jam is thick enough by placing a small amount on a saucer so that it can cool quickly. Add the reserved granadilla pulp to the boiling jam and leave to stand for 10 minutes.
The jam should be placed in sterilised jars while it is still warm but only seal the jars once the contents have cooled.