Carefully rinse beet so as not to damage the skin. Break off leaves. Place beets in a saucepan and pour enough water to cover. Bring to a boil and cook for about 30 minutes. Remove from boiling water, rinse and peel under running water. Remove the peel from the ginger and cut into thin strips. Peel onions and cut into rings. Layer beets alternately with onion rings and ginger in a large glass jar. Boil the water with wine vinegar, salt and sugar, pour hot over the beets. Close the jar and leave to infuse for at least 2 days. The beet can be kept in the refrigerator for at least 3 months.