Ohi'a 'ai are red, a bit crunchy, nicely sweet, and absolutely delicious. In Hawaii, where they grow prolifically, they are more commonly known as mountain apples. In other parts of the Pacific, they are also known as Malay apples.
They range from pale pink to brilliant, dark, ruby red. They're crazy shiny, slightly pear-shaped (or heart-shaped, if you're a romantic), and when they're in season, they seem to be absolutely everywhere.
Some people liken their shape, taste and texture as apple-like, just like their color. Ohi'a 'ai are remarkably shiny, like a well polished apple, but their lovely soft, yet somewhat crunchy texture is much more like a ripe Comice pear than any apple. The flavor, too, has a light sweetness and delicate flavor that isn't foreign to someone who has eaten a pear or two in their time. Inside the shiny skins is soft, cream-colored flesh that also will remind many people of... yes, you guessed it: pears. At the center of ohi'a 'ai are dark, hard seeds. In this way, ohi'a 'ai seeds seem much more like date pits than anything else (and no, you shouldn't eat them).
Ohi'a 'ai trees (scientific name Syzygium malaccense) were brought to the islands by Polynesian settlers from Malaysia. The wood was used for building and the fruit for eating and making dyes. The trees are in the myrtle family, related to guava and eucalyptus. The flower blossoms and resulting fruit sprout not just anywhere along the branches but on the truck, too. A tree full of the shiny fruit is a spectacular sight. Much like plums, these trees tend to be prolific fruit producers, and those fruits seem to ripen all together.
Ohi'a 'ai are widely available at farmers markets, farm stands and roadside honor bins in Hawaii throughout much of the summer and into fall. The trees grow in tropical forests and low-lying valleys on the humid windward sides of the different Hawaiian islands. They are a common garden tree on the islands, and when the fruit are in season, extras are often given to tree-less friends and neighbors. Since, as mentioned above, the fruit on a tree tend to all ripen at once, it's tricky for a single household to keep up (they're like Hawaiian zucchini in that way!). Ohi'a 'ai are usually eaten fresh, but they can be dried or pickled, too.
Mountain apples have paper-thin skins. Actually, their skins are even thinner than paper. They are more simply the idea of skins. Their bare existence means that ohi'a 'ai require extremely delicate handling. Seriously. Even bumping into each other in a bag on the way home from a farmers market can create bruising and cracks in the delicate exteriors.
Their fragility is, of course, part of their appeal. It seems unlikely they'll get shipped to the mainland anytime soon. That's what makes ohi'a 'ai such a decidedly island experience. You can find them at a farmers market in Hawaii, on the Big Island.
Treat mountain apples gently, and know that they tend to only last a few days (at most) before soft spots set in. Give them a quick rinse before eating, and enjoy them out of hand as a refreshing snack.