There are two major types of persimmons commonly available in America: fuyu and hachiya. Fuyu persimmons are squat and round and can be eaten out of hand like an apple. They have a crisp, almost waxy texture, and a sweet flavor slightly reminiscent of gingerbread.
For hoshigaki, however, you will need to use hachiya persimmons. These are longer and pointed. When unripe, they are firm, but as they ripen, the flesh becomes gelatinous. Unripe hachiyas are not edible. The flesh is intensely tannic and bitter. To make hoshigaki, though, you want them still unripe and quite firm.
Select fruit that has at least an inch of stem attached. If the flesh of the fruit is at all soft, do not try to use them for hoshigaki; instead, leave them on the counter on their shoulders and allow to ripen. When soft, the flesh can be enjoyed like pudding, or used in baked goods.
Don’t worry about black marks on the skin of the fruit. This is caused by sunburn but does not affect the end product in this case.
Trim away the sepals at the top, getting as close to the stem as possible. Using a sharp peeler, peel the skin of the persimmon off all over the fruit, being careful not to bruise the flesh. The peeled fruit will be slippery, and the goo will form a sticky residue on your skin.
Hang the persimmons
Tie twine around the stems of the persimmons, and hang them in a place with good airflow and humidity, like a garage or a basement. If possible, it’s also good that the fruit get some exposure to sun. Make sure there is space between the fruit. Traditionally, the persimmons are hung on two ends of the same piece of string and draped over a 2-inch piece of bamboo, usually in open air in a sheltered location.
Massage the persimmons
For the first week, do not touch the persimmons. When th
e slippery surfaces have become tacky and begun to firm, gently massage the persimmons for a few seconds at least once every day. As the tannins in the fruit break down, the flesh will become soft and the fruit will become pliable, at first only near the surface, and eventually all the way to the core. The leathery surface will darken and turn brown.
Be very careful when massaging the persimmons. When the flesh is at its softest, it may burst through the skin.
If any persimmons develop mold on the exterior, discard them.
Keep massaging until sugar blooms
After about a month to six weeks, the fruit should wither down, and a powdery white bloom will form on the surface. This is the natural sugars forming on the outside of the fruit, and an indication the hoshigaki is ready.
If the sugar does not bloom within six weeks, but the fruit is dark and firm, your environment may not be humid enough. Try pulling the fruit down and putting them in an airtight container like a large mason jar, or a zip-top bag. The sugar should bloom within two to three days.
Enjoy your hoshigaki as a snack or slice them into salads and desserts.