Science

Measuring Phylloxera’s Impact on the World of Wine

GuildSomm’s Kelli White examines how the aphid-like insect has transformed viticulture

illustation of Phylloxera Vastatrix smoking a cigar
Photo courtesy of Edward Linley Sambourne.

Turmoil raged around the globe, but the near century between the conclusion of the Napoleonic Wars in 1815 and the advent of World War I in 1914 was a time of rising prosperity for much of Europe. The mad rush to colonize the world had largely subsided, and the major powers within Europe and Russia had stopped fighting over the pieces. Mostly. Cities swelled as the Industrial Revolution transformed and urbanized the landscape, and the New World was being plundered for raw materials to feed its machines. Meanwhile, the population—especially within France—enjoyed an improved standard of living. The citizens celebrated their rising status with an increased thirst for wine, and land under vine swelled accordingly.

Advancements in technology had shortened the journey between continents. Liberated from the vagaries of the wind, steam-powered ships sliced through ocean waves at record clips. Their hulls, made first of wood and later of steel, bulged with exotic bounty. Globalism had descended. The world had been cracked open and untold delights had tumbled out, to be collected and disseminated across Europe. The tomato and Italy, lovers in a past life, had been united—but not all the New World’s gifts would prove so benevolent.

One particular pest, an aphid that came to be known as Phylloxera vastatrix, was especially damaging. This microscopic insect, native to the Mississippi Valley of the eastern United States, practically destroyed all the world’s vineyards once freed from its native land. What reassembled in its wake was the blueprint for the modern wine industry that we know today.

The explosive transformation of phylloxera cannot be overstated. It is not known what vessel bore this pestilence to European soils, nor even precisely when. All we know is that at some point, packed in damp earth, an otherwise innocent-looking bundle of vines made its way across the Atlantic, a million tiny Oppenheimers riding on the roots.

First Symptoms, First Responders

In 1866, a grower in the southern Rhône, roughly halfway between Avignon and Orange, reported the death of a block of vines. In the span of a few growing seasons, the leaves had withered and dried, and then the vines themselves succumbed. Two years later, with the infection clearly spreading, the French government set up a three-man coalition to investigate. The dead vines, once exhumed, revealed nothing but diseased and rotted roots. The plants directly adjacent to the infection, however, swarmed with microscopic yellow bugs. The committee recognized the aphid as a close relative of the oak phylloxera. To underscore the particularly deadly nature of this tiny assassin, they appended its name with vastatrix, Latin for “the devastator.”

What happened next is fascinating. The committee, led by Jules-Émile Planchon, Professor of Botany and Pharmacy at the Université de Montpellier, rejoiced in the discovery. Surely their sleuthing had uncovered the criminal, and the world could now move forward in seeking a cure. But instead of applause, they were rewarded with doubt and ridicule. As none of the three were insect specialists, entomologists publicly denounced their findings, sure that a lone aphid was incapable of such wholesale destruction. This was damaging enough to the commission’s cause, but the worst attacks came directly from Paris, the seat of France’s medical community. There, the leading minds believed phylloxera was merely the symptom of some inherent vine malady, not the actual cause of death, and called for an investigation into what factors (climate, soil, too many years of asexual reproduction) might be weakening the plants. This mirrored the dominant medical philosophy of the day: that people did not get sick from external forces such as germs, but became ill due to internal imbalances of the body, a holdover from the ancient concept of humors. As such, the Paris contingent argued that phylloxera’s role was no greater than that of a vulture, drawn in by the carrion perfume of the already dying vines.

To understand this schism, one must take a step back and consider this moment in the evolution of human thought. Phylloxera struck when France was, for all intents and purposes, fresh off the Enlightenment. This was a period (from the late 1600s to the early 1800s) during which the scientific method began to supplant the more mystical, superstitious thinking of yore. Needless to say, the transition did not happen uniformly, nor in one fell swoop. So while science was more scientific than ever in the mid-1800s, it was still a fairly primordial field. Louis Pasteur, whose work would prove fundamental to our understanding of microbial life, including fermentation, was early in his career at this point. Charles Darwin published On the Origin of Species in 1859 but was still considered something of a radical. And Gregor Mendel, that famous Austrian monk with his pea plants, proposed a genetic theory of trait inheritance in 1865, but his work would remain largely unknown until the turn of the century. In short, France’s collective medical brain was stuck between two modes of thinking, with strong opinions and abundant pride on either side of the divide.

Initially, the phylloxera-as-symptom camp had the greater numbers and, as they were based in Paris, the more official platform. As time passed, however, an increasing amount of evidence stacked in favor of phylloxera-as-cause. In 1869, a massive flood kept a fully infected vineyard submerged for several weeks. The proprietor was delighted to see the vines looking healthier than ever the following growing season. The bug, he surmised, had drowned. It was also noted around this time that phylloxera never seemed to strike extremely sandy vineyards. These observations furthered the notion that phylloxera itself was the culprit, as only when relief was provided from its incessant sucking would vines thrive.

A full seven years would pass between the discovery of Phylloxera vastatrix and its official pronouncement as the cause of the malady, years in which the debate between the two sides played out publicly via a series of letters and editorials that were rife with incendiary comments, professional jealousy, and personal attacks. Reading through these exchanges today is not unlike watching a horror movie wherein the protagonists bicker about which way to run while the killer circles ever closer. Indeed, phylloxera racked up quite the body count while the scientists squabbled. After chewing its way through the Languedoc and Provence, the louse reached Bordeaux in 1869, where it infected 100,000 of the region’s 170,000 hectares. Having consumed its fill of Claret, phylloxera turned and headed north. By the time of consensus in 1875, the knife’s edge was mere inches from the delicate throats of Burgundy, the Loire, and Champagne.

Origin Story & The Quest for Kryptonite

While the powers that be in Paris searched for clues to the plague inside the vine, Planchon and his colleagues set to work examining the bug. A major point of interest was its origin. Where had phylloxera come from? Planchon’s original published findings had made their way across the ocean and the desk of C.V. Riley, the state entomologist of Missouri. Riley recognized the aphid as similar to an American species that seemed to feed only on the leaves of grape vines and suggested they might be one and the same. Planchon tested this hypothesis in 1870 by placing infected leaves from American vines near pots planted with vinifera. Within a few days, the bugs had migrated underground to feast on the European roots. This not only confirmed that they were the same insect, but also that the origin was likely American.

With phylloxera rightly fingered and its birthplace revealed, the scientists’ energies now focused on a cure. The French government had opened the floor to the general population, with a generous bounty on the head of the pest. The result was a torrent of fantastical home remedies, each more preposterous than the last, more than one involving some combination of urine and garlic. Burning proved ineffectual, as did prayer. Flooding enjoyed a moderate success but was limited in application, as only the flattest vineyards could be physically submerged for the recommended length of time (40 days). Plus, the treatment had to be repeated every year. Sand was also a weapon of choice. Not only were holes dug around the trunks of vines and filled with the stuff (a laborious enterprise), but multiple new vineyards were developed on dunes and beaches. Proximity to the waves proved problematic, however, as more than one of these vineyards washed out to sea.

Ultimately, two main strategies emerged as the best way to fight phylloxera, each with their own ardent camp. The “Chemists” recommended the use of pesticides while the “Americanists” thought salvation would be achieved by using native American vines in some form, whether through direct planting, the creation of European-American hybrids, or grafting. As with the phylloxera cause/symptom debate, this battle stoked the notoriously passionate French into near hysteria.

Initially, the Chemists held the advantage, having both history and the government on their side. Years before phylloxera had made itself known, another American scourge had threatened Europe’s vineyards: oidium (powdery mildew). According to Giulia Meloni and Johan Swinnen, oidium caused French wine production to decrease from 54 million to 11 million hectoliters between 1847 and 1854. Thankfully, in 1855, it was discovered that regular sulfur dusting could alleviate the danger, and production rebounded almost immediately. Such a complete triumph led many scientists to believe a similar solution was possible for phylloxera, and significant government and private funding was thrown the way of chemical research.

After an elaborate series of trial and error, carbon disulfide (CS2) was tapped as the phylloxera asphyxiate of choice. This was an imperfect solution, as not only was CS2 extremely dangerous (its fumes are highly combustible), its application was both tedious and costly. To keep phylloxera at bay, CS2 had to be administered around the vines twice yearly, both in the spring and in the fall. A large, syringe-like device was engineered as the delivery mechanism, and gas had to be injected at multiple points per square yard. Soil and climatic requirements were extremely specific. The ground had to be porous enough to receive the gas, but not so friable that it would escape easily. Also, if rain came too soon after treatment, reapplication was necessary. The elaborate, expensive nature of this process ensured that only the wealthiest vignerons with the most prestigious landholdings could keep the practice going for any length of time.

Meanwhile, experiments with American vines were yielding mixed results. Some producers had simply replaced their old vines with American ones, but the wines were disagreeable. Hybrids were more successful. The hope was that cross-breeding would marry European flavors with American fortitude, but the results were never so glorious. Most hybrids were of limited utility, proving only partially resistant to phylloxera and often only partly palatable. Still, they became a popular option internationally, and though hybrids are now outlawed in most of Europe’s appellations, they continue to play a significant role in many wine regions, especially in the more marginal corners of the New World.

It was growing increasingly clear that grafting European varieties onto American rootstock was the only real and permanent solution. Various scientists had been beating the drum for this for years, but the strategy was viewed by many as a last-ditch effort to be tried only when all other options had been exhausted. The fear was that the American roots would taint the flavor of the wine; even after this had been largely disproved, the underlying prejudice was difficult to overcome. After all, American vines were the very agents of evil that had carried phylloxera to French soil.

The first laws officially sanctioning grafting onto American rootstock were passed in 1878 and 1879, but even then, the practice was confined exclusively to the south, and only to the most heavily infected zones. Grafting remained prohibited in Bordeaux until 1881 and in Burgundy until 1887, when desperate growers effectively forced administrators’ hands. But grafting was complicated business. Not all American rootstocks were impervious to phylloxera, and certainly not all were suited to the various soils and climates of France. The identification and development of proper rootstocks took years of experimentation and was not without false starts. More than one bad recommendation was made in the early years, meaning growers who might have spent their last dimes to replant were once again faced with fields of dead and dying vines. Still, the collective vineyard of France pushed on, and it is estimated that by 1900, two-thirds of French vines were bound to American roots.

The Old New France

Phylloxera transformed France in several profound ways. One of the most dramatic changes was to the scale of the industry. Viticulture had expanded more or less steadily since the French Revolution; per Rod Phillips, area under vine reached its apogee in 1874 with 2,465,000 hectares, roughly three times France’s total plantings today (the Organization Internationale de la Vigne et du Vin reported 791,000 hectares in 2014). Most wine regions shrank after phylloxera and some disappeared altogether, while only a handful (notably the Languedoc) grew in proportion.

Viticulture was completely overhauled. Prior to phylloxera, most of France’s vineyards were field blends rather than organized blocks of varieties, and were generally propagated en foule (“in a crowd”) via layering. In this method, a cordon, or even an entire vine (as with provinage), was buried until it set roots. The result was a jumbled mishmash of vines at densities two-and-a-half to three times higher than is common today, and complex root systems that could be several hundred years old. Cépages adjusted as well. For most regions, phylloxera provided an opportunity to separate the wheat from the chaff, and countless poorly regarded vine types either experienced diminished plantings or were eradicated. And, of course, the use of grafted vines allowed vineyards to be planted in rows and along trellises, which modernized farming and opened the door to mechanization.

In truth, some of these changes were already in motion before phylloxera’s descent. For example, the area surrounding Paris was once carpeted in vines, the wine from which filled the cups of the nation’s thirsty capital. The expansion of the canal system and development of railways in the 1840s and 1850s suddenly gave the drinkers of Paris ready access to the more robust libations of the Languedoc, which was producing half of France’s wine by the 1850s. As a result, the greater Parisian vineyards and much of the Yonne was already in decline by the late 1860s. Over in Bordeaux, the oidium outbreak had caused a shuffling of varieties to favor those with resistance to mildew, and the finest houses were already working to rid themselves of the less prestigious wine grapes. Still, no matter the existing trajectory, there can be no question that phylloxera sped things along significantly. However devastating and expensive it may have been, it was also a heck of a shortcut.

Loire & Jura

Both the Loire and the Jura regions experienced dramatic transformations in the wake of phylloxera. Reportedly, before the outbreak, a full two-thirds of the Nantais was planted to Folle Blanche, Sancerre was predominately a red wine region, and Muscadet was nowhere near as prevalent as it is today. As with Sancerre, the Jura switched its allegiance from red to white grapes, and the entire appellation shrank significantly. According to Wink Lorch’s book on the subject, 62% of land under vine was lost after phylloxera, never to be replanted.

Alsace

Alsace underwent a particularly tumultuous time during the phylloxera outbreak, as the brief Franco-Prussian War saw the area annexed to Germany in 1870. The German response to phylloxera was faster and more severe than that of the French: Alsacian vintners were ordered to uproot and burn their vines, and leave the land fallow for a handful of years. When they were finally permitted to replant, the German government allowed them only hybrids; it would take Alsace’s return to French rule in 1918 for the hillsides to be returned to noble varieties.

Bordeaux

As previously discussed, Bordeaux was in flux by the time phylloxera struck. Historically, the area’s vineyards had been planted to dozens of different wine grapes, but there was already a movement to prioritize the varieties in vogue today. That momentum got a bump during the oidium crisis; by the time of the 1855 Classification, Malbec, which demonstrated a high resistance to mildew, was quite dominant despite its notoriously irregular fruit set. Phylloxera changed all that, as both Carmenère and Malbec proved difficult to graft and therefore lost real estate. Malbec still maintained a measurable presence in Bordeaux until the massive frost of 1956, when it was finally muscled out by more reliable and fashionable varieties.

Burgundy

Burgundy boasted fewer varieties than most regions before phylloxera but still enjoyed far greater diversity than is seen today. In his book Pearl of the Côte, Allen Meadows reports that by 1878 (the year of the first phylloxera sighting in Burgundy), only 43% of the red grapes grown in the Côte d’Or were Pinot Noir. The rest were Gamay. In addition, the interplanting of Chardonnay, Pinot Gris, and Aligote was common. During phylloxera, many less prestigious or Gamay-dominated ­vineyards were left to languish, as only the top producers could afford the expensive CS2 injections that kept the louse at bay. Famously, the last vineyards to be replanted onto grafted vines in Burgundy were Domaine de la Romanée-Conti’s Romanée-Conti and part of Richebourg. Both were pulled out in 1945, when the war made carbon disulfide impossible to come by, and were replanted in 1947.

Champagne

Phylloxera hit Champagne last; the bug wasn’t discovered in the Aube until 1888. While a late discovery might seem like a blessing, as the mysteries of and remedies for phylloxera had been figured out by that point, the timing was actually unfortunate. Much of France’s vineyard land had recovered by then, and production was once again robust. But France now had to contend with the international market that had sprung up during the infestation; suddenly, there was altogether too much wine. This glut resulted in an economic crisis, and many in Champagne couldn’t afford to replant until after the turn of the century. Some were just getting started when World War I turned their vineyards into battlefields.

Travails of war aside, Champagne experienced a similar makeover to that of France’s other wine regions. Vineyard land both shrunk (by the 1920s, the area under vine in Marne was half of what it was prior to phylloxera) and changed in composition. The permitted varieties winnowed appreciably, but many consumers are unaware of the handful of more archaic grapes that remain legally allowed in Champagne. These varieties include Petite Meslier, Arbanne, Fromenteau (Pinot Gris), and Pinot Blanc. While they represent only a small amount of planted area, a dedicated group of producers make a point to celebrate them, such as Laherte Frères and Aubry. There are also a few patches of own-rooted vines scattered throughout Champagne. The most famous parcels are the walled vineyards in Aÿ (Clos Chaude Terres and Clos St.-Jacques) that Bollinger uses to create its Vieilles Vignes Française bottling. Bollinger still farms these plots using the ancient system of provignage, which is quite laborious. Cyril Delarue, US Commercial Director for Bollinger, jokes that these small vineyards take the most work, requiring three to four times as much manual labor to cultivate.

Fraud & The Rise of the AOC System

The dramatic drop in production during the phylloxera infestation forced France to import a significant amount of wine. It also inspired a good deal of fraud. In addition to “raisin wine” created from dried Greek and Turkish grapes, unscrupulous producers were making “sugar wine” and “piquette,” created by steeping pressed grape skins in water and fermenting. Merchants were also cutting corners, blending wines from various regions and countries and marketing them as being from specific estates or prestigious growing areas. Champagne was the most immune to this last type of fraud, as it was one of the few regions to sell the majority of its wine in bottles rather than casks. Bordeaux was the next to adopt that practice, and in 1924, Mouton, Haut Brion, and Margaux switched to estate bottling.

Fraud was not necessarily a new development in the French wine industry, though certainly the scale of fraudulent activity reached a new high during phylloxera. The issue was that once French wine production recovered in the late 1880s and 1890s, the financially battered producers couldn’t compete against both international products and cheaply made faux wines. James Simpson, author of Creating Wine, posits that by 1890, raisin and sugar wines accounted for at least a sixth of French wine consumption. And these “wines” didn’t just disappear once actual production began to rise. With the market flooded, prices plummeted, and great unrest was sown among the growers. In 1907, over half a million people marched on Montpellier, a protest of unprecedented size. The startled government took notice, and while it had already begun heavily taxing imports and attempting to mitigate fraud, it now turned its attention to the creation and protection of appellations.

The 1935 Appellation d’Origine Contrôlée provisions didn’t sprout fully formed from the head of some official; they were the culmination of many small legal steps that began in the 1880s. First, wine was defined as being made from fresh grapes, then water additions were made illegal—another hurdle to raisin wine production. Next, the government sought to legally demarcate specific growing areas, such as Champagne and Bordeaux, and prosecute merchants who misrepresented a wine’s origin. Hybrids were then forbidden from inclusion in wines labeled with an appellation, and laws were passed that aimed to control viticulture and methods of production. While today the AOC system is sometimes decried as being too restrictive, none can deny its effectiveness at preserving regional identities and heritage. As a testimony to its success, it became the blueprint for almost every other appellation program established around the world.

International Ramifications

Prior to the triple American plagues of oidium, phylloxera, and peronospora (downy mildew), France was the world’s largest producer and exporter of wine. Within the span of a single decade, the 1880s, France’s phylloxera-induced wine deficit turned it into the world’s largest importer of wine. This had a massive impact on the global wine industry, boosting existing regions and inspiring the creation of new ones, some of which were informed by French vintners who had fled their homeland in search of new beginnings. Of course, phylloxera eventually spread far beyond France, which complicated the international market tremendously. The differing responses of the variously affected nations make for an interesting study.

Spain

One of the first nations to benefit from France’s crisis was Spain. France had looked to Spain to replenish its wine reserves since the first outbreak of oidium in the 1840s. Oidium had hit just prior to the development of Europe’s now extensive rail system, so Spain’s surge of viticultural growth was concentrated around major ports such as Alicante. As phylloxera came after the rails, wine regions in the center of the country could respond. Nationwide, Spain experienced a 40% growth in vineyard land between 1860 and 1888. As early as 1877, a preferential trade agreement was struck between the two nations, allowing for the easy flow of Spanish wine into France. According to Meloni and Swinnen, this allowed Spain to surpass France as the world’s largest exporter of wines, with France its biggest client. Though much of the emphasis was on bulk wine, some quality regions emerged. One of the most important was Rioja, where the influence of Bordeaux was already established through the training of Luciano Marqués de Murrieta and Camilo Hurtado de Amézaga (Marqués de Riscal) in the 1850s.

Two things ultimately served to stifle Spain’s incredible growth. First, phylloxera crossed national borders, destroying a third of Spain’s vineyards between the late 1880s and the first World War. Among the casualties were Priorat, which shrank from 5,000 to 600 hectares, and Navarra, which lost around 99% of its vines between 1891 and 1896. The other major blow came when French vineyards started to recover in the 1890s. With domestic production on the rise, imports became a liability, and France raised aggressive tariffs on Spanish wine in 1892. This was devastating to the Spanish economy, and vineyard land shrunk considerably in many regions.

Germany & Switzerland

It’s arguable that these countries share not only a common language but also a mutual love of order and efficiency. For most nations, phylloxera’s advance proved impossible to stop. But while colder regions have the advantage of a longer winter dormancy, it was ultimately the organized ruthlessness of the German and Swiss approach that spared their vineyards the worst of phylloxera. Once an infection was discovered inside Switzerland, the vineyard, surrounding vines, and land were treated with enough CS2 to kill the roots and therefore the food source. This was followed by a strict and extended period of quarantine. The German approach was similar, according to George Gale in Dying on the Vine, but with the added flair of a petroleum soak, vine bonfire, a second CS2 application, and a military cordon to guard the site during decontamination.

Greece

Greece and France have a long history of trade, especially as it pertains to wine. But in the aftermath of phylloxera, Greece had a very specific role to play: supplying raisins to desperate winemakers lacking raw materials. Following the Greek War of Independence (1821–1832), Greece began exporting raisins to the British market for use in their puddings. While the British were formidable consumers, the French market that opened in the 1870s was insatiable. French winemakers would steep raisins in warm water and ferment the resulting liquid into something resembling wine. The demand became so great that Greek land dedicated to raisin production jumped from 24,000 hectares in the 1860s to 114,000 hectares in the 1880s, with much of the growth concentrated in the Peloponnese. This rapid increase cemented raisins as the dominant agricultural product of Greece, as well as their primary export.

But the recuperation of French vineyards in the late 1880s and the punishing tariffs and import limitations that they instigated in 1889 were devastating to the Greek economy. Per Wines of Greece, “The raisin crisis drove much of the agrarian population to abandon the countryside and seek a better life either in urban centers or in other countries. In some areas, such as the Peloponnese, this crisis resulted in severe social upheaval.” Meanwhile, as farmers rioted in central Greece, phylloxera had crept into Greece’s northern area by 1898. The pest quickly ravaged Macedonia and the area around Thessaloniki, and spread southward from there. Its progress was slow, however—the louse didn’t reach the Pelopponese until the 1960s, Crete until the 1970s. Records are imperfect, but local growers are convinced that countless rare indigenous grape varieties were permanently lost during the phylloxera crisis. Notably, Santorini remains phylloxera-free, hence its incredibly old vines and ancient method of cultivation.

North Africa

What transpired in French-controlled Algeria, Tunisia, and Morocco during and after phylloxera is both compelling and tragic. While a small wine industry already existed in North Africa, France’s phylloxera invasion spurred sudden and dramatic growth. This was especially true in Algeria, a full colony (Tunisia and Morocco were French Protectorates). During the crisis, the French government offered subsidies for vignerons in the south of France to relocate to Africa and build up the wine industry, an opportunity seized upon by some 10,000 farmers and winemakers. In Algeria alone, land under vine expanded from 17,000 hectares in 1878 to more than 60,000 hectares in 1885.

With their vineyards rebounding, the French government enacted harsh trade deals with foreign countries in the late 1880s and 1890s, but as Algeria was considered a part of France, it was exempt from such penalties. Algeria’s growth continued, and by 1960, it was the fourth largest wine producer in the world and the single largest exporter. That changed following Algerian Independence in 1962. Without easy access to the French market, demand plummeted, and Algeria’s domestic consumption was too low to absorb the surplus. Within a relatively short span of time, much of the vineyard land was grubbed up and the once prosperous industry effectively collapsed.

Australia & South America

Australia takes phylloxera very seriously. According to Vinehealth Australia, a phylloxera watchdog group, 74% of South Australia’s commercial wine grape vines are still planted on their own roots. This is a remarkable percentage, considering phylloxera found its way to Australian shores as early as 1877. As with Germany and Switzerland, the country managed to contain the threat via decisive and extreme actions. As soon as an infection was spotted, that vineyard was ripped up, the vines destroyed, and the land left fallow for many years. The strategy, known as “death by extinction,” was clearly a winning one. Today, Australia is divided into three zones: Phylloxera Exclusion Zones (PEZ), Phylloxera Risk Zones (PRZ), and Phylloxera Infected Zones (PIZ), with a five-kilometer vine-free buffer surrounding each zone of infection. So far, the bug has only been discovered in Victoria (where it did considerable damage), Queensland, and New South Wales, with the happy result that Australia boasts a high percentage of some of the world’s oldest vines. Even so, the government remains admirably vigilant, conducting aerial scans every three to five years, searching for clusters of weakened vines.

Meanwhile, down in South America, phylloxera has only a scant presence. It is effectively nonexistent in Chile and only menaces a few contained pockets of Argentina. South America was fortunate to receive its Bordeaux vine material just two decades before phylloxera hit, and only five years before the oidium outbreak. As in Australia, the majority of these nations’ vines are own-rooted. Interestingly, Chile and Argentina’s flagship grapes are Carmenère and Malbec, the very varieties that were effectively booted out of Bordeaux for not grafting well. I asked a handful of nurserymen about this rumored disposition, and all assured me that today there is no problem grafting either vine type. Dr. Andrew Walker, Professor of Viticulture at UC Davis, offered the following conjecture, “There is no inherent genetic reason that a particular variety would reject a graft. That really only ever happens when either the scion or the rootstock is virused—cells at the graft union will kill themselves off to avoid contamination. Both Malbec and Carmenère were historically known to turn red in the autumn. That typically suggests at least some degree of virus. My guess is that the majority of 19th-century Malbec and Carmenère were likely virused, and therefore hard to graft, while today’s growers have access to clean plant material.”

North America, Then North America Again

Though phylloxera is native to the United States, it was contained to the eastern half of the country until sometime in the 1850s or 1860s. Prior to its first official diagnosis in Agoston Haraszthy’s Sonoma vineyard at Buena Vista in 1873, California’s West Coast enjoyed over 100 years of own-rooted winemaking, rustic though it may have been. At first, the pest seemed to spread slowly, and vineyard land exploded during the 1880s. By the 1890s, however, the aphid had achieved critical mass and quickly undid much of the previous decade’s accomplishments. In Napa Valley alone, vine plantations shrank from around 20,000 acres in the beginning of the decade to about 3,000 by its conclusion. In response, the California state legislature established an investigatory commission, and also asked the University of California to establish a viticulture department.

The devastation was not restricted to the north of the state by any means. While France’s mistakes (flooding, CS2 reliance, poor rootstock recommendations) were incredulously repeated in California, phylloxera worked its way through the state. Though salvation eventually arrived in the form of the Rupestris St. George rootstock, any major recovery was forestalled by the terrible national economy and the increasingly influential temperance movement. And so, the briefly triumphant American wine industry limped along until Prohibition laid it temporarily to rest in 1920. Following 1933’s Repeal, California wine had to start over from scratch, but multiple forces were aligned against it. The Great Depression, World War II, and a national preference for cocktails and sweet wine kept investment at bay. By the 1960s, things had started to look up, and a small but growing number of dedicated producers were crafting wines of serious merit. And after the 1976 Judgment of Paris, California experienced a wave a development that has yet to crest.

The dramatic growth of the 1960s, 1970s, and 1980s seemed to herald the coming of a golden era for California wine. There was only one problem: some 60 to 70% of the new vineyards had been planted on an insufficiently resistant rootstock. In 1958, a report was published by viticulturalist Lloyd A. Lider that recommended AxR-#1 as a superior all-purpose rootstock to the finicky St. George. What the report failed to mention was that AxR-#1, a cross between a Aramon (vinifera) and rupestris, was susceptible to phylloxera. This particular chink in the armor had been documented by the French, the Sicilians, and the South Africans during the first wave of the global phylloxera epidemic, and again in a 1921 report by F.T. Bioletti of the University of California.

That AxR-#1 was ever recommended is baffling enough, but to make matters worse, nine years would pass between phylloxera’s reemergence (1980) and UC Davis’ official denouncement of the rootstock. By that time, it is estimated that around 50,000 acres of vines needed to be replanted, at a total cost of over one billion dollars. The silver lining of this tragedy was that California vintners could completely redesign their vineyards, which resulted in a refining of varieties statewide. Notably, 1991 saw Cabernet Sauvignon finally overtake Chardonnay as the most widely planted wine grape in Napa Valley.

And yet, American optimism persisted. Oregon, whose wine industry really didn’t get started until the 1970s, planted a significant amount of vines on their own roots before phylloxera was discovered there in 1990. And nearly all of Washington State’s vineyards remain ungrafted and uninfected. Christophe Baron of Cayuse in Walla Walla thinks it’s only a matter of time before phylloxera descends. “I was the first to plant grafted vines in Walla Walla in 2000. I still farm lots of own-rooted vines, but don’t feel comfortable putting all my eggs in one basket. I need to protect my investment!” Many believe that Washington’s dry conditions and extreme winters have also kept phylloxera at bay.

Deconstructing Phylloxera

While certainly a level of institutional neglect is responsible for California’s double serving of phylloxera, part of the blame rests with some long-misunderstood elements of phylloxera’s lifecycle, as well as its complex relationship to rootstocks. Fundamental to the enduring mysteries of phylloxera is the fact that it is a microscopic insect that spends much of its life underground. This makes it incredibly difficult to observe. According to UC Davis’ Dr. Walker, much of the “known” biology of phylloxera for the last 150 years was at least part conjecture, extrapolated from the lifecycles of similar aphids.

Most accounts describe phylloxera’s lifecycle in five phases, including both winged and subterranean forms, and both sexual and asexual modes of reproduction. Underneath the ground, an entirely female, wingless population of phylloxera feeds on roots, reproducing asexually to turn out massive numbers of clonal offspring. Late in the growing season, a number of phylloxera (again female) are born with wings and migrate above ground, possibly due to population pressure. Though these insects have wings, they possess no muscles to power them, so they use them more like sails and fan out on the breeze, landing on the leaves of some nearby vine. These phylloxera lay eggs in the leaves which hatch into both male and female forms. Interestingly, these offspring possess neither wings nor digestive organs—they were conceived only to mate. Following intercourse, the male dies while the female lays a single egg in the bark of the vine, which winters over near a dormant bud. Meanwhile, the existing population of phylloxera is killed off by the winter cold. The egg hatches in the spring, producing a single wingless female who returns to the leaves to reproduce asexually. Sometime during the summer, a portion of her offspring returns underground to feed on the roots, starting the cycle all over again. Critically, as each female can lay up to 200 eggs at a time, only one insect is sufficient to spark a massive infestation.

While much of the above has been proven true, a few of details are dubious. Dr. Walker claims that the so-called “winter eggs” have rarely been observed in the wild, and what’s more likely is that a small but hearty portion of the phylloxera population is able to hibernate through the winter. Males are also rarely seen, and are therefore unlikely to be a reliable annual occurrence. What’s more likely, posits Dr. Walker, is that phylloxera acts in a similar way to nematodes, reproducing asexually until some environmental stress triggers the formation of a male. The purpose of this would be to induce genetic variance via sexual reproduction in the hopes of overcoming some difficulty, such as an incompatible food source.

When AxR-#1 failed in California, scientists claimed that the fault resided in the development of a new strain of phylloxera, Biotype B. This theory was championed by several faculty members at UC Davis and then-graduate student Dr. Stephen Krebs. Dr. Walker eventually joined UC Davis, and began working on the phylloxera problem with a focus on their genetic diversity within California. “It became clear to me almost immediately that there wasn’t so much a Biotype A and B, but many biotypes—or, more correctly, strains.” Each of these strains came with their own meal preferences, which made resistance fluid in concept.

“No rootstock is fully resistant to phylloxera,” Dr. Walker explains. “Phylloxera does feed on the roots of American varieties, but only on the tiny feeder roots, which replenish so rapidly, the vine can survive.” The fatal vulnerability of vinifera is that phylloxera can feed on its larger roots, causing swollen lumpy callouses called tuberosities. These often split, allowing various bacteria and fungi to infect the plant, ultimately killing it. “It is not phylloxera itself that kills the vine,” Dr. Walker continues. “Phylloxera is merely the agent provocateur that allows for the introduction of deadly pathogens.” Curiously, vinifera leaves are relatively immune to damage from phylloxera, while native American leaves can become covered in galls, though this will not kill the vine. “There is an inverse immunity relationship between resistance at the root and leaf level among vine types,” Dr. Walker adds.

So how did AxR-#1 survive so long before failing, and is Biotype B real or a government conspiracy? “The thing is,” Dr. Walker says, “after the first infection, it really takes 10 to 20 years for a vine to die from phylloxera attack, as the decline is slow. Long before the leaves start to whither, the vine is infected. The earliest measurable symptom is a decline in potassium in the must.” In that light, it is possible for a vine to survive in soils infected by phylloxera for a considerable amount of time. Also, the lifespan can be indefinite if the local population of phylloxera is not able to feed on the large roots. Though most of phylloxera’s reproductive cycle results in perfect clones, the odd sexual combination can result in the generation of increased genetic diversity. If a strain of phylloxera develops that is suddenly able to feed on a given vine’s major roots, it’s just a matter of time before the population reaches a fatal tipping point. While many viticulturalists might view this as paranoid, Dr. Walker insists the potential danger is real. “I’ve isolated strains that are capable of feeding on the root tips of almost all rootstocks, including many that are considered highly resistant. We don’t know whether this level of feeding has always been present or whether it evolved after many years in vineyards, but it bears studying and preparing for more aggressive strains of phylloxera.”

With phylloxera, there are no absolutes. Much of the pest’s behavior depends on its environment. Just as it cannot thrive in too sandy a soil, phylloxera’s dormant season is greatly extended in cold climates, and the resulting truncated growing season means fewer reproductive cycles for phylloxera, and therefore fewer bugs. Similarly, climates with very dry summers like in California will suppress the winged form, which also slows the advance. John Williams of Frog’s Leap claims that farming can also be a factor. “I am of the belief that it was the widespread use of drip irrigation that made the phylloxera infestation in the 1980s so deadly.” When Williams had purchased his Red Barn Ranch, the vineyard was planted on AxR-#1 and was in rough shape. By converting it to dry farming, his vines lasted far longer than for many of his colleagues. “Drip irrigation raises the rooting zone of a vine closer to the surface,” explains Williams, “which is where phylloxera lives.”

Whether or not you view Dr. Walker’s warnings as realistic, history is replete with teachable moments about not dropping one’s guard around phylloxera. At the very least, it is worthwhile to keep the conversation going. “I don’t give any talks on phylloxera now because no one cares anymore,” laments Dr. Walker. “But they should!”

Le Goût Américain

Phylloxera irrevocably changed the world of wine, but did it alter wine itself? The answer to this question lies in whether you believe that grafted vines produce different-tasting fruit than own-rooted vines.

“I can confirm to you that when you use American roots, you change the taste of the wine,” Loïc Pasquet asserts. Pasquet is a bit of renegade in Bordeaux. His brand, Liber Pater, works with own-rooted vines, high-density planting, and historic varieties (for example Castet, Marnay Coolant, and Saint Macaire) in order to recreate the type of wine produced at the time of the 1855 Classification. With grafted wines, he says, “One cannot make a vin de terroir, only a varietal wine. For example, Cabernet Sauvignon was created for gravelly soil with oceanic weather. If you use ungrafted Cabernet Sauvignon, it can only do well in these conditions. If you graft, you can plant anywhere, but you lose the specificity of cépage [or] terroir. You lose the true taste of the wine.”

Allen Meadows has more experience tasting pre-phylloxera Burgundies than most. “I would argue that there is a difference in wines made from grafted and ungrafted vines,” Meadows admits. “But it’s less about taste than texture. There is a different density and weight, and it’s almost as if the tannins themselves have a different quality.” The difficulty, he says, is in knowing whether that variance is from grafting or is a result of the differences in vine age, density, and training. Still, he’s inclined to finger the graft. “If you really believe that a vine has a life below ground and a life above ground, and the one below feeds and nourishes the vines, it seems to me that making such a fundamental change to the structure of the vine would result in a measurable difference in the taste of the wine.”

Christophe Baron of Walla Walla’s Cayuse is one of the few people who are regularly able to compare wines from own-rooted and grafted examples of the same variety, with roughly the same vine age, planted on identical soils. He agrees with Meadows that the difference is primarily textural. “When you read old articles or texts about pre-phylloxera wines, they always talk about that smooth velvety quality in the mouthfeel, on the palate. And that is really what it is. My grafted vines are completely different; the wines have more tension, more grip. And this is true across a range of red varieties.”

Under the umbrella of the Turley label, Tegan Passalacqua (whose social media handle, @ownrooted, indicates his level of interest in the matter) works with several old vine vineyards, both grafted and ungrafted. He also believes that grafting can change the taste of a wine, but takes it one step further by proposing that different rootstocks will do this in different ways. “The main thing I can speak to is Zinfandel. And the biggest thing with Zinfandel is that own-rooted vines tend to ripen more evenly inside the cluster.” This, he believes, is because the St. George rootstock—upon which most old vine Zinfandel is planted—is notorious for uneven fruit set. He also thinks that Wente clone Chardonnay, so highly regarded for producing “shot” berries (small, seedless grapes with a high skin-to-juice ratio), owes at least part of its reputation to its long association with St. George. “People tend to focus on the clones when discussing wines, but the rootstock can either magnify or reduce a given clone’s tendencies dramatically.” Indeed, aside from disease resistance, some of the factors a rootstock can influence include vigor, evenness of ripening, timing of ripening, and nutritional uptake. The results may be subtle, but variances in any of those categories is bound to alter the final impression of the wine.

Not everyone is convinced that grafting alters the taste of wine in a significant way, or at least to a more profound degree than that seen between different clones and rootstocks. Napa Valley viticulturalist and winemaker Steve Matthiasson says, “I think it is a myth that own-rooted vines are in a different category than rootstocks. Yes, they are a different root system…but all rootstocks are different from any other rootstock. Own-rooted vines are grown from cuttings, just like rootstocks, so it is already an unnatural root architecture compared to a plant that grew from a seed that started with a tap root.” Matthiasson continues, “This question of rootstock versus own-rooted was debated in France for [over] 75 years back in the 1800s, and the conclusion was that rootstocks show terroir just as well. Rootstocks can help with sustainable [agriculture] by being more drought- or pest-tolerant (beside the obvious phylloxera tolerance), so I hate them getting a bad rap. It’s like dry farming versus deficit irrigation, or organic versus biodynamic. There needs to be a place for being reasonable and focusing on important stuff like pesticide use, habitat, soil conservation, labor issues, [and so on].”

Tyler Thomas, winemaker for Dierberg and Star Lane Vineyards in Santa Barbara, cautions against overly romanticizing the subject. “The discussion of own-rooted versus grafted vines remind me of the old vines versus young vines debate, in which the default romantic position is that old vines make better wine.” He continues, “In my career, sometimes I have been able to taste the difference between old and young vines from the same vineyard and sometimes I can’t. As with own-rooted vines, I believe it is a case-by-case issue. And one of the reasons that old vines are kept is because they historically performed well. Underperforming vines would likely have been ripped out before achieving great age, so there is a kind of pre-selection. As wine lovers, we sometimes forget to apply that kind of logic.”

No matter where you stand on the qualitative debate, it’s hard not to feel curious about these relics from our vinous past. Fortunately for wine lovers, there exist enough pockets of the world where phylloxera has not penetrated—Canary Islands, Chile, Contra Costa County, Colares (and those are just the C’s!)—that we can still experience the taste of wines planted on their own roots. Such portals to the past are slowly closing, however. As recently as 2005, one of Bollinger’s ancient vineyards succumbed to phylloxera, and even where sandy soils forbid the louse, threats such as real estate development and the financial pressure to plant higher producing or more popular varieties loom. Pre-phylloxera bottles from classic regions are becoming increasingly difficult to find, and recent fraudulent activity has hobbled confidence in those that remain.

I have been lucky enough in my time as a sommelier to try pre-phylloxera bottlings of Bordeaux and Burgundy on a handful of occasions. And the few tablespoons I enjoyed were magical enough to make me immediately nostalgic for a period of time with which I have no real connection. Still, it was the romance of their rarity that transported me, rather than a discernible difference in taste, per se. And yet, when I think of those wines today, I daydream of a world in which even a faint attempt at quarantine in the 19th century might have preserved some of the ancient ways. Considering the monumental impact of phylloxera, the world would be a very different place. Who knows? Maybe no serious wine list would be complete without a vertical of Gouget Noir from central France. And maybe it would be considered classic instead of fringe. We can’t say for sure. All we can do to connect to that diminishing heritage is to seek out those rare bottles and the few remaining phylloxera-free regions. We can raise our glasses, contemplate the wines’ texture on our tongues, and toast the forces beneath our feet that we can’t see for squinting but can make the whole world jump.

Note: For the purposes of this article, the term “hybrid” only refers to crosses between European and American varieties. There are many popular hybrids created through crossing two different vinifera vine types, and almost all rootstocks are hybrids of different American vine types, typically some combination of vitis rupestris, vitis riparia, and vitis berlandieri.

– Written by Kelli White

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GuildSomm is a nonprofit international membership organization for wine professionals that promotes education and community. Articles, podcasts, and videos are publicly available on GuildSomm.com and cover varied topics on the world of wine. Members have access to in-depth educational materials, an active online community, masterclasses, and more.

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