The history of raising grapes in Yamagata Prefecture is very long. In the Meiji era, European and American species were imported. Yamagata Prefecture grows the third most grapes in Japan; the Delaware grape is the most grown in Yamagata Prefecture.
Poor soil and well-drained land are ideal for growing grapes. Grape-growing lands in the prefecture satisfy the conditions of long hours of sunlight and large differences in temperature between day and night as well as little rain while the grapes mature. The cold night winds in August and September help grapes ripen and sweeten. If you look at grape trellises during the harvest season, heavy bunches of grapes are everywhere.
Maturation and sweetness enhanced by differences in temperature
Grape maturation progresses from the upper side of a bunch, which is the main stalk side. When grapes are not matured, the upper side is sweeter and the lower side, which is the tip side, is less sweet in general. As maturation progresses, the sugar content on the lower side increases and comes close to that on the upper side.
The white powder covering the skin is called bloom and is a natural waxy ingredient that comes up to the surface of the fruit skin. The white powder repels rain, morning dew and more to protect grapes from diseases and prevent water evaporation to protect grape freshness.
Grapes can be kept at room temperatures, but the quality cannot be kept for long. Please eat the grapes as soon as possible. Wrap them in newspaper or put them in a plastic bag to prevent drying, keep them away from direct sunlight and store them in a cool and dark place or in the refrigerator. Leave a little of the main stalk, cut the grapes into smaller bunches and keep them. You can taste sweeter grapes by taking them out of the refrigerator 20 to 30 minutes before eating them.