Diospyros virginiana In respect to the power of making heartwood, the persimmon rarely develops any heartwood until it is nearly one hundred years old. This heartwood is extremely close-grained and almost black, resembling ebony (of which it is a true variety). It is a common misconception persimmon fruit needs frost to ripen and soften, called bletting. Some, such as the early-ripening varieties "pieper" and "NC21"(also known as "supersweet"), easily lose astringency and become completely free of it when slightly soft at the touch—these are then very sweet, even in the British climate. On the other hand, some varieties (like the very large
Hybrid wood Hybrid wood Hybrid wood or wood hybrid systems (WHS) is a multilayer composite material, composed on the surface of a skin made of composite wood (WPC) adhering to an underneath structural core, in general aluminum. Invented in Japan in 2008, this technological evolution is based on wood composite technology which was conceived in 1972 by Sadao Nishibori and patented in 1983 to substitute threatened exotic wood species. WHS are not fibre-reinforced plastic (FRP). In truth, speaking of hybrid wood profiles only makes sense when the outer layer – the composite wood – and the core – aluminum – are adhering