Lack of diversity makes grapes vulnerable to climate change.

The ancient Romans were great lovers of wine. They developed viticulture throughout what’s now Italy and ensured that everyone, from slaves to aristocrats, had access to wine on a daily basis. Scientists have long wondered how similar Roman wine was to what we drink now, and they’ve finally got an answer.

A new study, just published this week in Nature Plants, has found that modern-day grape varieties are almost genetically identical to what was drunk in the days of ancient Rome. This was discovered by collecting grape seeds from nine ancient sites in France, some dating back 2,500 years. It required what NPR describes as “a monumental cross-disciplinary effort by ancient-DNA researchers, archaeologists and modern-grape geneticists.” From its report:

“Of the 28 ancient seeds that the researchers tested, all were genetically related to grapes grown today. Sixteen of the 28 were within one or two generations of modern varieties. And in at least one case, the researchers found that consumers are drinking wine from the same grapes as medieval Frenchmen 900 years ago: the rare savagnin blanc… In other cases, we are drinking almost the exact same wine that Roman emperors drank — our pinot noir and syrah grapes are ‘siblings’ of the Roman varieties.”

While lovers of history and terroir may take great delight in this knowledge, it does put wine makers and drinkers at risk in the face of climate change. Its pedigree and timelessness is precisely what makes it vulnerable. NPR cites Zoë Migicovsky, a postdoctoral researcher from Dalhousie University: “If these varietals are genetically identical all over the world … it means they’re all susceptible to the same pests and diseases as well. We [will] need to use more chemicals and sprays in growing [them] as threats advance.”

The good news is that there are many more grape varieties out there that could be bred for greater resilience. Elizabeth Wolkovich, co-author of a study published earlier this year, told the Harvard Gazette,

“The Old World has a huge diversity of wine grapes — there are more than 1,000 varieties planted — and some of them are better adapted to hotter climates and have higher drought tolerance than the 12 varieties now making up over 80 percent of the wine market in many countries. We should be studying and exploring these varieties to prepare for climate change.”

There are a few roadblocks, however. Europe has strict labeling laws: “For example, just three varieties of grapes can be labeled Champagne, or four Burgundy.” But this is slowly changing. The council in charge of Bordeaux’s labeling laws just decreed that 20 new grape varieties will be allowed for use in a wine labeled as bordeaux. From the Washington Post:

“The move, already approved by French national regulators and the legislature, will allow grapes such as marselan and touriga nacional to join the traditional blend. The varieties must have an advantage in terms of climate change or environmental protection (as in disease resistance, requiring fewer chemical treatments).”

Another challenge is convincing shoppers that the label shouldn’t matter so much. In the New World, where labeling regulations aren’t nearly as strict as they are in Europe, winemakers don’t experiment as much as they should because people are fixated on buying specific grape types. Wolkovich said, “We’ve been taught to recognize the varieties we think we like.”

She hopes that wine makers and drinkers alike will realize that just because certain grape varieties were well-suited to a particular climate 2,500 years ago does not mean they always will be. If we want to keep those bottles on our dinner tables for decades to come, we’d be wise to expand out of our comfort zones – and perhaps discover a world of wine that the Romans could only dream of.