In 1920, the Eighteenth Amendment to the United States Constitution created yet another setback for the American wine industry. The National Prohibition Act, also known as the Volstead Act, prohibited the manufacture, sale, transportation, importation, exportation, delivery, or possession of intoxicating liquors for beverage purpose. Prohibition, which continued for thirteen years, nearly destroyed what had become a thriving and national industry.

One of the loopholes in the Volstead Act allowed for the manufacture and sale of sacramental wine, medicinal wines for sale by pharmacists with a doctors’ prescription, and medicinal wine tonics (fortified wines) sold without a prescription. Perhaps more important, Prohibition allowed anyone to produce up to two hundred gallons yearly of fruit juice or cider. The fruit juice, which was sometimes made into concentrate, was ideal for making wine. People would buy grape concentrate from California and have it shipped to the East Coast. The top of the container was stamped in big, bold letters: caution: do not add sugar or yeast or else fermentation will take place! Some of this yield found its way to bootleggers throughout America who did just that. But not for long, because the government stepped in and banned the sale of grape juice, preventing illegal wine production. Vineyards stopped being planted, and the American wine industry came to a halt.