The thick, spiny green peel of the soursop hides a sweet and tender inside, sort of like a fruit version of Oscar the Grouch. Also known as guanabana, soursops offer a flavor that is reminiscent of both pineapple and strawberries, with a light and creamy undertone that calls coconuts to mind. Extracting the juice requires nearly as much work as getting Oscar to smile, and is every bit as worth the effort.
Choose the Sweetest Fruit
Grown all over the world, soursop is therefore in season from January to November, depending on where you are located. Choose fruit that is pale yellow-green in color. Squeeze the fruit gently to see how ripe it is. Ripe soursop should be soft but still firm. If a soursop is unyielding and hard, it is not ripe enough, and if it is mushy, it's either overripe or has been bruised.
Prepare the Fruit
Rinse the soursop in cool or lukewarm water. Pat it dry with a clean, lint-free dishcloth or a paper towel. Peel away the skin with a sharp paring knife. You can also cut the soursop in half and scoop the pulp out with a spoon. Either way, you must cut away and discard the tough stem in the center of the fruit. Place the soursop pulp in a large mixing bowl and remove the seeds. Using your fingers in the simplest and most efficient way to remove the seeds, though this may take you a fair bit of time.
Extract the Juice
Soursop pulp is thick and meaty, so you will have to macerate it to get as much juice out as possible. The easiest way to do this is to place all of the pulp in a blender or food processor with 2 to 3 cups of water for each soursop, and blend or process the pulp until it is completely smooth.
Strain the Pulp
Just as with orange juice and lemonade, whether to leave the pulp in your drink is purely a matter of preference. If you prefer to serve and enjoy your soursop juice pulp free, the traditional way to strain it involves pouring the soursop juice into a large bowl, lined with a square of fine cheesecloth larger than the bowl. Gather the edges of the cheesecloth together and twist them closed. Hold the twisted edges securely with one hand while you squeeze the juice out of the cheesecloth with the other. A quicker way is to pour the juice slowly through a fine sieve into a pitcher, pressing it through with a wooden spoon.
Flavor the Juice
Soursops are not actually all that sour, so taste the juice before sweetening it. If you prefer a sweeter version, add sugar or agave nectar to taste. You can mix soursop juice with sweetened condensed milk for a thicker and more decadent treat. Flavor the juice with cinnamon or shaved vanilla beans if you like.