Try putting it inside a bowl of flour for 24 hours. Cover it with the flour.

Is there other ways? Ive also heard you should do that with vodka to get rid of the bitterness. What does the flour do?

You can try putting the perssimons in a paper bag with a banana or apple to ripen. they are very bitter when not very ripe.

So you can ripen them like any other fruit? How do you know when fully ripe????

they turn really orange and sometimes they get these black spots on them but you can still eat them. you'll know when you touch the perssimon , they will be very soft and mushy. They are so good when really ripe their like a soft sweet jelly. Yumm!!

There are some persimmons that are ripe before they're really mushy. Generally, the ones that kind of have a point (hachiya) do need to be mushy before you eat them. Persimmons that don't have a point but are kind of shaped like a flatter tomato (fuyu) can still be eaten while firm, though they benefit from being a little soft, like a ripe peach would be. Either way, when ripe the persimmon will be candy-sweet and delicious. Enjoy!