Persimmon trees classified broadly into two general categories: those that bear "astringent fruit" 【涩柿】(whilst unripe) and those that bear "non-astringent" 【无涩柿】fruits. An astringent cultivar, which is commonly cultivated in Japan known as “Hachiya,” is high in tannins and must be allowed to ripen fully until it attains jelly-soft consistency before being fit to eat. A non-astringent persimmon, on the other hand, contains less tannin and can be eaten while it is crispy, as in apples. Astringency can be removed by treating the fruit with carbon dioxide or alcohol.
During each season, persimmon tree bears numerous fruits that vary by cultivar from spherical to heart to flatten or squash-like in shape. They also greatly vary in size from as little as a few ounces to more than a pound. The color of the fruit varies from light yellow-orange to dark orange-red. The entire fruit is edible except for the seed and calyx.
Astringent varieties: Eureka, Hachiya, Saijo, Tamopan, Tanenashi, Triumph, etc.
我敢断言，加州柿子即使吃得很多也不会出现因为单宁造成的问题。
如果愿意的话，请搜索陕西师范大学张宝善等的《柿单宁研究进展》。
但中国比较多的架豆绝对需要做熟了才能吃。
Persimmon trees classified broadly into two general categories: those that bear "astringent fruit" 【涩柿】(whilst unripe) and those that bear "non-astringent" 【无涩柿】fruits. An astringent cultivar, which is commonly cultivated in Japan known as “Hachiya,” is high in tannins and must be allowed to ripen fully until it attains jelly-soft consistency before being fit to eat. A non-astringent persimmon, on the other hand, contains less tannin and can be eaten while it is crispy, as in apples. Astringency can be removed by treating the fruit with carbon dioxide or alcohol.
During each season, persimmon tree bears numerous fruits that vary by cultivar from spherical to heart to flatten or squash-like in shape. They also greatly vary in size from as little as a few ounces to more than a pound. The color of the fruit varies from light yellow-orange to dark orange-red. The entire fruit is edible except for the seed and calyx.
Astringent varieties: Eureka, Hachiya, Saijo, Tamopan, Tanenashi, Triumph, etc.
Non-astringent varieties: Fuyu (Fuyugaki), Gosho/Giant Fuyu/O'Gosho, Imoto, Izu, Jiro, Maekawajiro, Okugosho, Suruga, etc.
山楂，cranberry，之类也是。生的时候是涩的，煮熟基本就没有涩味了。
人和动物的味觉还是很有用的。比如橡子里单宁很多，但白橡树的橡子单宁就少得多，涩味也小。我观察一下，白橡树的橡子很快就被松鼠吃光光，红橡树的往往过了冬还会剩一堆。
北京冬天的柿子，很大，扁的，形状和左边的一样，硬的时候很涩，是不能吃的，要等到放软了才能吃。
在加州多年，同事邻居送给我自己家种的柿子，大约有三四家吧。都是扁的，中小型，不涩，硬的时候就可以吃。大概就是你图里的Fuyu。
今年一个新同事送我一袋柿子，小型，扁的。硬的时候很涩不能吃，一定要放得很软才能吃。不知道是什么品种。
据说抗生素性寒，而且是大寒。
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0ahUKEwiLx7H9idbQAhWFMyYKHZfmCcsQFgglMAE&url=http%3A%2F%2Fwww.paper.edu.cn%2Fjournal%2FdownCount%2Fjournal-1672-4291(2008)01-0099-07&usg=AFQjCNHit_wd4ciyLsn2AFdnaKju3A8qIA&bvm=bv.139782543,d.eWE
而那种高桩的吃两个个以上会觉得不舒服。
Fuyu 曾一次吃过七八个，很舒服。
梨子也不能超过两个。
某些时候貌似殊途同归，实际上是两条道路，归不到一起去，只能说是歪打正着。