The Great French Wine Blight was a blight which destroyed over 40% of French vineyards in the 1860s and 1870s. The blight had a serious impact on French winemaking and French culture, and gave some North American and European vineyards a chance to step in and fill the vacuum, becoming established as wine powerhouses in their own right. The history of the French Wine Blight illustrates the unexpected vulnerabilities which can be present even in very old crops.
This tangled story begins in the 1600s, when Europeans noted that European grape varieties would not grow in North America. They didn't understand why this might be, but settled for cultivating North American grapes, or grafting European grape varieties onto North American rootstock, which seemed to solve the problem. Although European colonists didn't realize it at the time, the problem was caused by phylloxera aphids, which destroyed the rootstock of vulnerable European grapes which had never been exposed to these aphids.
Surprisingly, despite all the traffic between Europe and North America, phylloxera did not reach Europe until the 1850s. Some researchers who have studied the Great French Wine Blight have suggested that the aphids may not have been able to survive on the sailing ships used for transit prior to the 19th century. By 1863, phylloxera was present in France and killing vineyards, but people were slow to realize what was going on, and a number of potential causes for the French Wine Blight were posited.
Ultimately, the French realize that the problem was aphids, and that these aphids had colonized Europe, making it impossible to eradicate them. In response, vineyards started grafting traditionally European grapes onto North American rootstock in France and other nations affected by the blight. In France, this process was known as “reconstitution,” and it was not without controversy, as some people felt that it compromised the integrity of French vineyards and wines.
Today, so-called “pre-phylloxera” vintages made before the French Wine Blight fetch a high price when they come up for sale. Some wine fans claim that the French Wine Blight fundamentally changed the nature of French wines and winemaking, and that pre-phylloxera vintages are noticeably different from wines produced at reconstituted vineyards. Given the numerous factors which can influence the taste of wine, especially after hundreds of years of cellaring, it is hard to determine whether or not these claims hold water.