For much of October 2020, temperatures hovered in the low 80s in the Grand Valley American Viticultural Area, a grape-growing region on Colorado’s Western Slope. But, within 48 hours, the unseasonably warm fall quickly devolved into a nightmare scenario for the region’s many farmers, including Bruce Talbott, a fifth-generation fruit grower in Palisade.
On the evening of October 26, 2020, temperatures plummeted to 14 degrees Fahrenheit. The next night, they dropped to 9 degrees. The sudden cold snap, which struck before Colorado’s grapes and other fruits had hardened off for the approaching winter, wiped out an estimated 70 to 100 percent of the state’s traditional European Vitis vinifera wine grapes, many with familiar names like cabernet sauvignon and merlot. “October 2020 hurt us very badly,” says Talbott, who is 63. “We came back the next year with between 5 and 10 percent of our grape crop.”
Most of the grapes that remained in Talbott’s vineyards after the devastating freeze were various cultivars of cold-hardy, hybrid grapes, which Talbott and other Colorado growers had been planting as a bit of an experiment.
These hybrid grapes, which researchers create by crossing European species with native North American grapes and then selecting for specific, preferred traits, are rising stars in the U.S. wine industry. Growers like them because of their ability to handle the cold, their resistance to disease, pests and fungi, and their overall reliability in the face of changing conditions.
Climate change is messing with grapes—and, thus, the wine industry as a whole—in myriad ways. Rising temperatures cause grapes to ripen faster and allow bugs and diseases to proliferate. Increasingly frequent and more intense wildfires lead to smoke taint. Excessive drought puts too much stress on the vines, which can lead to lower yields. Changes to rainfall patterns, coupled with higher temperatures, are leading to higher levels of humidity which, in turn, allow mildew, fungi and other diseases to overwhelm the vines. Grape-growers are also dealing with floods, violent hailstorms, unexpected frosts and other extreme weather events linked with climate change.
“Climate change scares the heck out of me,” says Kaibab Sauvage, who’s been growing grapes in Colorado for more than 20 years and recently co-founded Sauvage Spectrum winery. “Now what was unpredictable is even more unpredictable.”
Hybrids aren’t new—they date back to at least the 1860s—but, as the climate and consumer tastes evolve, they’ve been growing in popularity in recent years. In Colorado, for instance, hybrids made up just 1 percent of overall wine grapes planted in the state in the early 2000s. Today, they represent 20 percent, says the state’s viticulturist, Horst Caspari.
Hybrids are catching on thanks in large part to advances made by researchers at institutions like the University of Minnesota, Cornell University and the University of California Davis. These scientists are coming up with innovative new grapes to help address growers’ challenges and, in the process, they’re learning a lot about plant genetics, too. “We’re focused on bringing the best attributes of the European grapes that everyone is familiar with, like merlot and chardonnay, and combining that with the cold-hardiness and disease resistance that we get from the American species,” says Matt Clark, a horticultural scientist at the University of Minnesota.
Clark and fellow scientists conduct the bulk of their research on a 12-acre plot at the Minnesota Landscape Arboretum in Chaska, a southwest suburb of Minneapolis. At any given time, they’re growing upwards of 12,000 grape plants, many of which are genetically distinct from each other. Some of the plants are 40 years old, while others are brand new, planted very close together to see which ones outperform the others. “Plant breeding is really an exercise in killing plants,” says Clark. “We have lots of empty space because we are constantly thinking about how to remove them. If a plant is susceptible to disease or doesn’t survive the winter, that’s a pretty key way to get kicked out of the program.”
In late summer and early fall, researchers harvest grapes from the plants that survived, then take them indoors where a full-time university winemaker transforms them into 100 unique batches of wine each year. Scientists analyze the wines’ chemical makeup, then use that intel to inform their plant breeding decisions the following spring in the hopes of improving attributes like grape yield, fruit quality, wine quality and disease resistance, among others. One of the lab’s grape-breeding success stories, for example, is a cultivar named Itasca, which scientists developed by crossing two cold-hardy parents. Itasca is “even more cold hardy than either parent,” says Clark, and has the added benefit of being resistant to some mildews and pests. It makes a dry white wine with notes of honey, melon and violet.
They also use DNA testing to understand where desirable traits come from in the grape genome so they can select for those traits earlier in the breeding process. From the outset, DNA analysis confirms that parent grapes carry the genes researchers are interested in, which allows them to choose the right cultivars, or varieties, to pair up. When the offspring grow into seedlings, the researchers use DNA testing to screen them for the right characteristics and cull the plants they don’t expect to perform well. “Discarding bad plants early in the process means that we enrich the pool of good plants that will grow to produce fruit in four to six years,” says Clark.
Starting this fall, partially in response to extreme temperature swings like those in Colorado and elsewhere, they’ll also begin integrating technology that allows them to test the grapes’ cold-hardiness, in real-time, at various stages of the growing process. Already in use in some other labs around the country, the technique, known as differential thermal analysis, allows scientists to measure the tiny burst of heat grape buds give off when they eventually freeze. This gives researchers a window into a cultivar’s innerworkings, including the temperature at which it freezes at different times throughout the year, a reaction they believe the plant’s genetics control. In the long run, it should help them make strategic breeding decisions to produce plants that can better withstand chilly conditions.
And though climate change has always factored into the decision-making process, scientists and growers say it is looming larger with each passing year. Researchers aren’t selecting for climate adaptability itself, but rather, they’re breeding grapes that can survive in the face of climate change’s ripple effects. “Wine, when we stop and think about it, is really a luxury, but it’s been such a large part of human life for millennia that it’s inconceivable to think about how we move forward in a grape-free world,” says Clark.
Hybrid grapes aren’t a cure-all, however. For starters, they have a bad rap among some long-time winemakers, who are convinced that hybrids won’t produce the same high-quality wines as traditional European grapes. Many wine producers also believe that consumers simply won’t buy wines made from unfamiliar grapes, especially older generations of drinkers. In addition, hybrids that grow well in test vineyards in one part of the country may totally flop in others. The plants may excel at one attribute and fall short in other areas. Researchers also spend decades painstakingly developing hybrids and, more or less, they’re making their best guesses as to what the future holds. The climate is now changing so rapidly that researchers and breeders are having an even more difficult time predicting which plant characteristics will prove to be the most useful in the years to come. “And that’s the real rub of climate change is that, it’s not like the ball has stopped rolling—it’s rolling faster and faster,” says Jason Londo, a plant biologist at Cornell University. “When breeding for a very shifting climate, something that takes many years to develop, we are always playing catch up.”
Luckily, the once-poor reputation of hybrids is starting to change, especially as adventurous Millennials and Gen Zers start to buy and drink more wine. Those consumers are much less loyal to specific traditional European grapes than their parents are; younger buyers are also more interested in value, which hybrids can provide. That’s good news for the wine industry because hybrids may be the only sustainable path forward for some grape-growing regions. If climate change persists, erratic weather patterns will also continue to disrupt winemaking, making it even more challenging for farmers to grow a consistent, reliable crop, which they need in order to stay in the business. And with more hybrids in the vineyards, winemakers who were once reluctant to use hybrids will need to get more comfortable with the fruit if they, too, hope to stay relevant. “The only way we can survive in this industry is to adapt,” says Joe Flynn, winemaker at Plum Creek Winery in Palisade, Colorado. “Being in the field of agriculture, we’re dealt with what Mother Nature hands us and if we try to fight that and manipulate that, we’re going to lose every time. We have to just take what we’re given and make the best product we can with it.”