How to make astringent persimmons non-astringent
In recent years persimmons are often
seen in the
The former called fuyu gaki is non-astringent persimmon edible all the time.† The latter called shibu gaki is astringent persimmon which has very unpleasantly bitter taste (shibu means astringent).† Even when the fruit is well ripened, the unpleasant taste often remains.† The good news is, however, if the bitterness is removed in some way, the astringent kind is sweeter than the non-astringent.
Why the astringent persimmons taste bitter first of all?† The astringent persimmons contain large amounts of bitter substances such as catechin, gallocatechin, betulinic acid, and shibuol which are soluble in water.† Eating astringent persimmons without removing the bitterness is not only extremely unpleasant but can cause a severe health hazard. For example shibuol may polymerize when it is mixed with acid in stomach producing indigestible balls that could be removed only by surgery. (Recently, coca cola was found to resolve the polymerized chunk.)
We can, however, easily mimic tarunuki without using any sake barrel.† Namely, put astringent persimmons in a plastic containment with a tight lid, or alternatively in a zip lock plastic bug.† Before sealing the lid, pour a small amount (1/2 teaspoon) of white liquor, rum, brandy or whiskey.† Keep the persimmons in the containment for 2~3 days.† Voila, astringent persimmons then become only very sweet with no taste of bitterness.
What happens is the materials of bitterness become insolvable in water after chemically combining with alcohol.† The persimmons do not get any alcoholic flavor because the alcohol is consumed in the chemical reactions.
Author: Sho Nakamura††† 2011