Why the world’s most sought-after wine grapes face pandemic risks

When browsing the wine aisle for the perfect bottle to complement your meal or impress at a party, the variety seems abundant, shaped by factors like grape type, soil, climate, and aging process. Some of the most renowned include the French "noble wines"—cabernet sauvignon, merlot, pinot noir, chardonnay, riesling, and sauvignon blanc—which are celebrated for their premium quality and adaptability in various regions.

However, it turns out that many of these celebrated grape varieties share an unsettling trait with royalty: they are as genetically uniform as a royal family, having been cultivated in the same lineage for centuries, in some cases millennia.

"Scientists are increasingly worried that this could create the ideal conditions for a global pandemic," said Kevin Begos at a recent book event in New York City, where he discussed his book, Tasting the Past, which delves into the history, archaeology, genetics, and future of wine. Experts fear that a single ruthless pathogen could destroy grape varieties worldwide, much like the fungus Phytophthora infestans wiped out the common potato in Ireland during the 1840s, leading to the great famine.

The overwhelming majority of wine produced globally comes from a single grapevine species: Vitis vinifera. This domesticated grape boasts thousands of varieties and considerable genetic diversity, according to a 2010 paper in PNAS that examined the genome-wide genetic variation in over 1000 samples of V. vinifera subsp. vinifera and its wild counterpart, V. vinifera subsp. sylvestris. However, not all grapes share this diversity: Nearly 75 percent of grape cultivars are closely related, either as parents or offspring.

The most commercially successful wines are crafted from a small group of these genetically similar grapes. Sauvignon blanc, for example, shares a direct genetic link with cabernet sauvignon, cabernet franc, chenin blanc, and many others. This familial genetic closeness is a common trait among grapes.

Another complication arises in the way grapes reproduce in vineyards. Rather than naturally pollinating or growing from seeds, as one might expect, grape growers typically propagate new plants through cuttings of existing vines, effectively cloning them repeatedly.

This method ensures consistent flavor quality, which is ideal when uncorking a bottle of your favorite wine and knowing exactly what to expect. But this cloning practice has kept many beloved grape varieties in a state of genetic stasis for centuries. Take pinot, the parent of chardonnay and gamay, which has been cloned for over 2000 years. While its genetic makeup remains nearly unchanged, the pests and pathogens that target it have continued to evolve. "All those insects and pathogens and mildews that attack grape vines have been evolving," said Begos. "And they always figure out new ways to attack the grape vines."

Despite the widespread use of pesticides—260 million pounds were applied to wine grapes in California alone over the last decade—"the industry is losing the arms race to the pathogens," said Sean Myles, co-author of the 2010 PNAS grape genome study, in Tasting the Past. "It’s really only a matter of time. If we just keep using the same genetic material, we’re doomed."

The good news is that grape diversity may hold the key to saving rosé season from vanishing. Researchers are looking beyond the well-known noble varieties and their popular counterparts to explore old, wild, and lesser-known species, which, as Begos pointed out, "turn out to have natural disease resistance, and they've kept evolving."

The goal is to develop hybrids specifically chosen for desirable traits—not just pest resistance but also resilience to higher temperatures in a warming world, better adaptability to diverse soils, and other robust qualities.

One such initiative is VitisGen, a project funded by the USDA, involving teams from universities like UC Davis, Cornell, and the University of Minnesota. By analyzing the genomes of various grape varieties, they are building an extensive genetic database. They are also experimenting with crossbreeding, some of which involves traditional methods, such as hand-pollinating grapes.

Begos tells Mytour that their primary focus is developing grape varieties resistant to downy mildew (Plasmopara viticola), a potential scourge similar to the potato famine. If left unchecked, it can lead to total crop loss.

When selecting traits, flavor likely won’t be one of the attributes they’ll be extracting from wild grapes, which, according to Begos, "are really kind of terrible." (In Tasting the Past, he quotes wine experts who describe the flavor of a fox grape as a mix of "animal fur and candied fruits.") The focus is usually on hardiness. For instance, the concord grape in your child's PB&J is known for its toughness. By combining its hardy genes with, say, the spicy flavor genes of the syrah grape—another gene identified by the researchers—they may be able to create a resilient hybrid.

"The University of Minnesota has already made strides in identifying cold-resistant wine grape genes and successfully breeding them into new varieties that have wowed even the most discerning critics," says Begos. He highlights a 2015 top 10 wine list from New York Times food critic Eric Asimov, with number two on the list coming from hybrid grapes developed by UM.

You can contribute to wine diversity by being adventurous with your choices—try a grape you've never heard of or explore blends from unfamiliar regions. Look for organic and small wineries that are experimenting with ancient cultivars and innovative varieties. And don’t shy away from a future with genetically modified grapes. We've been altering them ever since we began cultivating them. As Begos notes about these efforts, "At heart, they’re unlocking flavor, disease-resistance, and growth genes that may be tens of millions of years old. To me, these scientists are doing exactly what the ancient Babylonians, Egyptians, and Greeks did: refining wine grapes to produce the tastes we enjoy."