Do you know what this fruit is?
Yes, the answer is persimmons, 柿（かき） in Japanese. It is my favourite winter fruit. Unlike most other fruit, it is very sweet but not sour at all and it is full of goodness, such as antioxidants and potassium.
The only trouble is that all unripe persimmons are very bitter!
The bitterness （渋み、しぶみ） of persimmons is caused by a chemical called “tannin” which is often used to dye fabric and leather. Apparently, some “tannin” is water-soluble and other tannin is not. If your persimmon contains the former, you feel the bitterness in your mouth but apparently all this water-soluble tannin in persimmons changes into the other tannin in time, whether or not that happens quick enough to eat them fresh. Some bitter varieties need to be dried for all of their tannin to change its property. However, those sold in greengrocers can be made sweet quicker.
The method I was taught as a child is to store the persimmons buried in uncooked rice and leave them there for a week or two. It is easy for Japanese people to do because they usually have a container full of uncooked rice at all times at home. However, it is not that easy to do in Australia.
Other methods that worked for me are:
+ wet the hull (the leafy part) with a strong liquor such as vodka, pack them in a plastic bag and leave them sealed for several days
+ put persimmons with other fruit such as apples and bananas in a plastic bag and leave them sealed for several days
Also, although I have not tried myself:
+ Get a piece of dry ice and wrap it in a newspaper. Put the wrapped dry ice in a plastic bag with persimmons and leave them sealed for a few days. – Apparently this is what green grocers in Japan usually do before selling them in shops to make sure they are sweet.
+ Soak a persimmon in warm water (about 40 °C) overnight – apparently it is not as nice as other methods but you can do this if you can’t wait for a few days.
I hope you can find some nice persimmons to enjoy this winter!
Next week, I will write some more about persimmons.