Soursop, also known as guanabana (Annona muricata), is a tropical fruit native to the Brazil region of South America. It is a relative of the custard apple, another tropical fruit, and got its name from its typical acidic and sour flesh. Trading and cultivation helped soursop trees spread throughout Central and South America and to the Bahamas, West Indies, and Florida. Early explorers shipped the trees back to Europe and from there they spread to tropical regions in Southeast Asia, Africa, and Australia.
Soursop trees can only be found in tropical areas and require plenty of water and warmth. They have low branches with evergreen, oval leaves that have an unpleasant odor. Wild trees can reach heights of 30 feet. The trees produce single flowers in the spring on their trunks and branches. These flowers are several inches long and have a yellow-green color. Pollinated flowers develop into soursop fruit over the course of several months. Unlike other tropical trees that produce hundreds of fruits per year, the soursop tree only produces a couple dozen fruits annually.
The fruit of the soursop tree has an oval shape and tends to be four inches to a foot long. The fruit can weigh up to 15 pounds. It has a leathery, dark-green skin studded with large, soft spines, giving the fruit the appearance of a prickly pear cactus pad. Fruits are harvested when their skin changes to a yellow-green color, their flesh softens, and their spines can easily be removed. The inner, edible flesh of the fruit is generally brilliantly white, fibrous, and juicy. The flesh is divided into several dozen to hundreds of tiny segments that can be pulled apart by hand. A few segments contain one smooth, black seed in their centers that is mildly toxic. The taste of the flesh ranges from sweet to very sour with tropical flavors, depending on the variety of soursop plant.
Fresh soursop fruits are not commonly found outside of their growing regions because they are extremely perishable. When buying fresh soursop fruit, look for ones that have a yellow-green skin and yield slightly to the touch. Ripe fruits will keep in the fridge for only a couple of days. During this time the skin may turn black, but the flesh inside will be perfectly fine. Soursop fruit also freezes well for longer storage. Canned and frozen soursop fruit, as well as soursop syrup and juice can be found in many Hispanic markets.
Sweet, ripe soursop fruits are generally eaten raw by removing the skin and pulling or cutting the fruit into segments, discarding the seeds. The fruit is often used in fruit salads or served alone with a bit of sugar and cream. It is also pureed into a white juice and mixed with sugar, milk, or water. Pink or green food coloring is often added to make the juice more appealing. Canned juice is sold throughout Central and South America and in the Philippines. The juice is also used in preserves, syrup, custard, and ice cream. Immature soursop fruits are often eaten in Southeast Asia. The fruit is roasted, boiled, or fried to make it tender. The flesh is reported to be mealy and has a flavor similar to roasted corn.