Seeds of the Amur grape.
Grapes can be preserved at -40C frost (three winter months) and ripen at +15C. Yes! It's possible!
But do not expect even a hint of sweetness from wild forest grapes (until the winter sub-zero temperature freezes it, it will not become sweet). These are very small and very sour grapes, but you will not find grape juice tastier than from it, wine tastier than from it, compote tastier than from it.
Grows in poor clay soils, about 2-3 inches of poor black earth is sufficient. Comfortable growing and fruiting temperatures in summer from +10С to +25С, in winter from -40С to -1. Rain and wind are familiar to him. Grows well in the shade.
(Seeds are taken only from plants growing in the wild taiga.)