日本ナツメ Another Jujube tree

 日本ナツメの実もそろそろ色づいてきました。一言に「日本種」と言ってもバリエーションはいくつかあるようで、数年前に地元JAで買ったトゲトゲの日本種の実と、今年の８月に買った苗の実とでは、葉や実の形が随分違います。共通点は、実が小さいこと。これは仕方ないです。幸いこの苗はトゲ無しなので世話がしやすい。この写真の実は、苗が届いてから開花した花の実。今年はこの小さい状態で終わりそうです。間引きと試食のために小さい実を毎日ポリポリ食べていますが、酸っぱくてジューシーで美味しい。酸味と果汁は、ナツメにとって稀で貴重な要素です。

The fruits of the Japanese jujube tree is ripening.  There are several types of common Japanese jujube trees.  The tree I bought several years ago was very thorny and the shapes of leaves and fruits were quite different from those of this tree which I bought in August this year.  The commonality is that the fruits are small.  This new tree is thorn free which makes it easy to look after this plant.  

The fruits in this photo are from the flowers that came after the plant was delivered to me.  Due to the short time in which they had to grow, it seems that this is all they can do for this year.  I have been tasting these tiny ones for the purpose of thinning, but they tasted so juicy and beautiful with definite sourness.  To me, juiciness and sourness in jujubes are rare and precious factors.

以下の４個は苗が届いた時点で開花していた花からの実。これくらいの色づきが果汁たっぷりです。

These 4 fruits are from the flowers in bloom at the time of plant delivery.  At this stage, the fruits are ripe.

色づきの度合いで糖度がどう違うか実験です。まずは右端の最も色づた実から糖度計を当てていきます。

I wanted to see if getting brown had correlation with sweetness.  I started measuring the sugar content with the one on the extreme right.

46.8%

46.9%

47%

46.9%

ほんとかいな、と思うくらいの高糖度です（あくまでも糖度計によるとですが）。しかも色づき具合はあまり糖度に重要ではなさそう。青い実を試食していたときは甘味を感じていたけど、それはしっかりした酸味のおかげで甘味を感じているだけだろうと思っていましたが、実際に糖度も高いようです。

They all show incredibly high sugar content (assuming that my gadget is working all right).  Interestingly, the degree of colouring seems irrelevant to the sugar content.  While I was eating the young fruits, they tasted sweet but I kept thinking that it was due to the relatively strong acidity that enhanced the sweetness.  I now know that this common jujube variety can produce very tasty fruits.