They are the best
    in the beginning of September,
 when they are more than ripe but not
overripe. They are soft, slightly wrinkled,
and the pulp is dark yellow or light brown.... Then they
 are the sweetest. Which does not mean they are the best. For
some people they are the best, for the others the best are those
earlier ones, hard, green inside, rather acid than sweet.... Both are
 not shiny. They are matt, because coated with grey waxy bloom. It can be
wiped off with a finger – this is the best method – and then we can see
shiny purple; those less ripe are more shiny – this is clear, since
 maturity (ripeness) has always been less shiny, ripeness (maturity) has
 always been closer to unclearness (blurness)..... Certainly, the best
 fruits are on the very top of the tree. To reach them you have to change
 yourself into a bird, or to shake the tree strongly, but then you
need to protect yourself against plum-hail, though not too much
 really since plums won't hurt you, rather pat – mind
quite a lot of plums will be lost in the tousled
 grass, what a pity!    <<<