Commercially, there are generally two types of persimmon fruit: astringent and non-astringent.
The heart-shaped Hachiya is the most common variety of astringent persimmon. Astringent persimmons contain very high levels of soluble tannins and are unpalatable if eaten before softening. The astringency of tannins is removed through ripening by exposure to light over several days, wrapping the fruit in paper for heating it, and/or artificially with chemicals such as alcohol and carbon dioxide which change tannin into the insoluble form. This bletting process is sometimes jumpstarted by exposing the fruit to cold or frost which hastens cellular wall breakdown. These astringent persimmons can also be prepared for commercial purposes by drying.
The non-astringent persimmon is squat like a tomato and is most commonly sold as fuyu. Non-astringent persimmons are not actually free of tannins as the term suggests, but rather are far less astringent before ripening, and lose more of their tannic quality sooner. Non-astringent persimmons may be consumed when still very firm to very very soft.
There is a third type, less commonly available, the pollination-variant non-astringent persimmons. When fully pollinated, the flesh of these fruit is brown inside -known as goma in Japan, and the fruit can be eaten firm. These varieties are highly sought after and can be found at specialty markets or farmers markets only. Tsurunoko, sold as "Chocolate persimmon" for its dark brown flesh, Maru, sold as "Cinnamon persimmon" for its spicy flavor, and Hyakume, sold as "Brown sugar" are the three best known.
Before ripening, persimmons usually have a "chalky" taste. They are generally only eaten when ripe and soft.