Ah, another bizarre Puerto Rican fruit! When you first arrive in Puerto Rico there are all kinds of odd things growing in your yard, your neighbor's yard, along the road or in the jungle. Some of them can be found at a roadside fruitstand and others you may see once and never again. The first questions are: What is it? What can I do with it? When it is ripe? How do I process it? I find a lot of the local fruit wonderful and a bunch of it nasty. A lot of things people eat here involve eating and spitting out lots of seeds, fibers, and pits. A lot of the fruit here have weird textures which are disturbing at first. Guanabana is one of the "disturbing textures" ones. The juiced fruit has the texture of man stuff. Yup, I said it. Man Stuff. The tree is a nice enough looking tree that will get spiky (soft spiky) football sized dark green fruit on it.We have been eating them for a couple months now so I suppose it is a spring fruit. The fruit is dark green and hard as a rock one day and bird pecked the next so you have to be watching if you want to harvest it. Seriously - one day it is very hard and the next day will have dropped to the ground. With all our fruit I make daily rounds looking for birds (easiest way to tell if something is ripe), fallen fruit or almost ready fruit. Once you pick it it looses its attractive dark green color and turns black and disgusting looking. Never fear, the fruit is still good! Once the birds have pecked a little hole in the fruit it is time to harvest. You just cut around that part. Inside is a soft, fragrant white flesh with hard black seeds. The seeds are covered with pulp and you just press the flesh through a sieve (I like this big holed one). Don't put this fruit in the blender/food processor or the seeds will ruin your blades. When you press it through you get a lovely bowl of man stuff. Slippery, slimy and a little frothy! I pour it into ice cube trays and freeze it. I store the cubes in the freezer in baggies to add to smoothies or simply make a guanabana smoothie with the cubes, a little soy milk and that's it! No sugar required. It makes a nice ice cream or sorbet also.
The only other thing I have done with it is use it as the liquid in pancakes. I had soursop pancakes in Fiji once. I suppose you could make "limbers" which are the adult version of a popsicle. The taste is refreshing - kind of like banana, a not-sweet pineapple...kind of hard to describe. It is one of the few fruits that isn't overly sweet. So don't let those fruit drop. Definitely don't just eat it (funny texture and too many seeds). Try substituting it for liquids in baking maybe or curries and report back...