The zorza, or zoria, zorza północna, kalwila polska, is an ancient apple variety, probably Ukrainian or Russian in origin, described for the first time only at the end of the 19th century. They usually ripen in Poland in the last ten days in September or early October.
Hardy and healthy, they are very tolerant of low temperatures; their thick skin is yellow with shades of reddish colour. The round, flat-shaped apples are large to very large (0.5 kg and over), their consistency is rather hard when first picked, then it is crunchy and fragrant.
The trees, with spherical leaves and slightly sloping branches, are planted in autumn or early spring; the first year after planting they are not productive, but they have to be watered frequently to guarantee abundant growth, then they can be slowly harvested, bearing large but not very many apples.
Sparse productivity and the large size of the apples are among the reasons the zorza apple has lost the interest of apple growers. As with other ancient varieties, it is not well adapted to modern intensive methods.
The apples are excellent in pies and salads, and being adapted to long conservation, they are traditionally eaten in winter, from December to March, fresh or cooked in composts.