As a shortcrust pastry dough, apple dumpling dough should resemble fine breadcrumbs before water is added. Once water is incorporated into the dough and kneaded, it should be firm but soft.
Shortcrust pastry dough typically has half the amount of fat as flour, so if you are using two cups of flour, then use one cup of butter or shortening. Because there is such a high fat content in the dough, make sure the bowl, butter and water are very cold. After cutting the fat into the flour to resemble breadcrumbs, add just enough cold water to make the dough firm. Gently knead the dough until it is soft, making sure it is not over-worked. Wrap in plastic and refrigerate for at least an hour prior to use.