Section 29 of the Volstead Act allowed 200 gallons (the equivalent of about a thousand 750 ml bottles) of “non-intoxicating cider and fruit juice” to be made each year at home. Initially “intoxicating” was defined as anything more than 0.5 percent, but the Bureau of Internal Revenue soon struck that down and this effectively legalized home wine-making.
Consequently, for a brief period, the Volstead Act of 1920 seemed to offer a secondary outlet for the agricultural products of the Napa Valley, and the cost of grapes shipped to home winemakers rose as a result. But it didn’t last. Why?
Looking through the agricultural commissioner’s crop reports from 1921 to 1934 for Napa County, it’s difficult to see the impact of the Volstead Act on the harvest tonnage. Yet, when one looks deeper at the value of those premium grapes a sobering sense of reality must have left grapegrowers with a terrible dilemma.
Figure 1 is a graph showing the tonnage that was harvested between 1921 and 1934 — the years the Volstead Act was in effect. It reveals that tonnage harvested remained relatively high, averaging over 20,000 tons per year
But the graph in Figure 2 tells a different story: The price of grapes initially fluctuates between $80 per ton in 1921 down to $45 per ton in 1923, then returning to about $75 per ton in 1924. But then, in 1925 grapegrowers in the Central Valley started shipping their inferior grapes, and the price of Napa Valley grapes started to tumble. Within seven years, the price per ton for Napa Valley grapes collapsed to a low of less than $10 per ton. So, even though the harvests were high or above average, the values of those grapes were never realized. According to official crop reports, many vineyard owners never even bothered to harvest, and fruit rotted on the vines.