In the sixteenth century, Portuguese explorers disembarked in Japan, bringing with them gunpowder, Christianity, and the many cultural practices that come with it.

For the next fifty years, Japan accepted Christianity, and the religion spread quickly around the island. But in 1587, Toyotomi Hideyoshi issued an edict that expelled Christianity. This marked the beginning of a strict persecution of Christians, which intensified ten years later.

In 1597, Hideyoshi banned further conversions and executed twenty-six Franciscans as a warning to others. As this caused Japanese Christians to go into hiding, very few records exist of the practice of Christianity in Japan after this point.

Now, however, a rare document has surfaced, which indicates that the tradition of winemaking endured for several decades of the seventeenth century. A lord of the Hosokawa clan made regular orders of wine from 1627 to 1630. This wine was produced from wild grapes and black soybeans. The report claims that the wine was meant for “medicinal purposes,” but its connection to Christianity could suggest that this was an excuse. Perhaps the Hosokawan lord was attempting to covertly procure wine for religious practice. 

Then, in January of 1633, the Hosokawa clan was ordered to move from the Kokura Domain to the Higo Domain. It is believed that the Hosokawa clan was no longer permitted to make the wine once they reached Higo. At that time the Higo Domain was less tolerant towards Christians, and may not have appreciated the practice. As persecution increased through the seventeenth century, continued wine production may have been seen as disloyal to the shogunate. 

So the researchers from Kumamoto University concluded that Japanese wine production ceased as a direct result of Christian persecution.

Source: Aleteia.org