There are two kinds of persimmons: the Fuyu, the kind you can eat right away, and the Hachiya, the kind you can't (until they are very ripe). If you bite into an unripe Hachiya persimmon, it is if you just drank a tea, where the tea leaves have been sitting in the tea pot for hours. This astringent flavor is due to the high level of tannin in the fruit.
We have a Hachiya persimmon tree in the garden. The tree is full of fruit in the winter. I decided to get a ladder and climb up the tree to get a couple of the persimmons because the birds have been eating all the fruit.
The other day, I tried to eat one of the persimmons and it was so bitter that it left my tongue numb. I had to spit out the fruit immediately. I will have to be a bit more patient until the persimmons ripen. I really like persimmons, the flavour is unique. Apparently, they provide us with important nutrients such as beta-carotene, Vitamin C and potassium.