On one of my trips to China, someone plopped a grape cluster in my hands for me to taste. As I held it in my hands it seemed to weigh about two kilos. Later he sent me pollen from this grape. I used the pollen on one of our small-clustered, super hardy varieties. Here is the best of the progeny. Beautiful, multi-stemmed cluster form and clusters typically 500-1000g. And quite winter hardy. If it were only seedless!