It tends to dry out the mouth and causes the mouth parts to cling together. It is not advisable to consume the unripe fruit. The best way to cleanse the mouth of astringent persimmon discomfort is to eat a fully ripened fruit. Ripe fruits become soft which can burst when falling from the tree. Soft fruit also has a short shelf life.
Most trees ripen their fruit over a two to four week period.
Some trees hold their fruit well into winter. Late maturing trees benefit wildlife and generally aren't used by man except as a food source for hunters. This late fruit should be consumed carefully as large poorly masticated consumption can develop into stomach bezoars. Very few cases have been recorded. These tannins look like specs of dirt when pulped but pose no health hazard.