Here’s the answer to your question from another thread:
There is a lot of hear say and speculations about the many ways to remove astringency from persimmons…most will work but have serious disadvantages:
Freezing works very often but destroys the structure of the flesh, the flesh gets an unpleasant glassy-silicon like structure. The fruit cannot be kept once you thaw them, they will start to rot if not consumed.
Placing the persimmons close to other ripe fruit like apples or bananas will hasten the softening process but it will also turn the flesh to a mushy state instead of gelatinous like when it naturally softens.
The alcohol treatment has the same effect as the ripe fruit method…
The only method that I can recommend to every persimmon grower is the CO2 treatment like it is commercially done with most of the kaki production in Europe. This treatment is very simple and can be done at home. All you need is a soda stream…if you do not have this already than this is perhaps a good time to purchase one.
Here is how it works: all you need is a decent sized airtight plastic bag (no punctures!!!). Put your freshly picked astringent persimmons in the bag until half full. Squeeze the top of the bag tight and suck the air out using your mouth/inhaling. Stick the nozzle of the soda stream carefully in the opening where you just sucked the air out and push the button of your soda stream so the bag fills with CO2 gas. Tie the top of the bag with a piece of binding wire to keep the CO2 gas in. Put the bag with persimmons in a box or preferably a bucket with lid so that you can close it airtight. Leave this for 48 to 72 houres at room temperature. After this procedure your persimmons will still be firm but without astringency and very important: your persimmons will not rot and you can still store them. They will even go on to turn gelatinous like all persimmons do eventually. This method requires some testing because some varieties need only 48hrs while others may need 72hrs. you can easily test your variety using only a pair of persimmons and raising or lowering the treatment time until you have reached perfection.
One of the varieties that can easily be treated is Nikita’s gift…