Grapegrowers in New York’s Finger Lakes region battle subzero temperatures, severe mildew and a short growing season. In other words, it’s hard enough for producers to make high-quality vinifera wines on the steep slopes along Seneca and the surrounding lakes. Farming biodynamically—a demanding practice that goes beyond organics in how it asks vineyard managers to replace the synthetic treatments they have long relied on—would seem nearly impossible.
But Fred Merwarth and Oskar Bynke, co-owners of the pioneering Finger Lakes estate Hermann J. Wiemer, were compelled to try. “We had been going down the road towards dialing into single-site expressions, and we were very curious if biodynamic farming would help us capture more of the nuances of each site we farm,” says Merwarth.
Pushing limits is completely in character for Merwarth, who began working at Hermann J. Wiemer in 2001 and officially bought the estate from its namesake founder in 2007. Back in the 1970s, Wiemer was a Riesling trailblazer, determined to prove the grape’s quality potential in this cold region. “As growers have realized Riesling’s reliability here, we have also come to respect its incredible ability to express the region's immense diversity of soils and mesoclimates,” Merwarth explains. “Riesling shows its sense of place like very few varieties can.”
Under Merwarth’s direction, Wiemer was the first winery in the region to bottle single-vineyard Rieslings. A specialist in cold-hardy varieties, he’s constantly exploring the potential of new clones and rootstock combinations at the Hermann J. Wiemer Grapevine Nursery, where nearly 200 different vine types are planted and sold to growers around the country.
The journey towards biodynamics began in 2003, when Merwath began eliminating all herbicides and synthetic additives and introducing cover crops and organic fertilizers. Next he switched to only native yeast fermentations, instead of adding cultured yeasts. By 2015, he was itching to push the concept of ecosystem health even further. The principles of biodynamics, which treat the whole farm as an ecosystem and focus on improving soil health and building up biodiversity, appealed to him.
“We want to be very experimental, but we are fanatical about using the scientific approach,” says Bynke. The goal was to obtain extremely precise and measurable data on how biodynamics impacts plant behavior, disease resistance and, ultimately, the profile of the wine in the glass. So, with the help of Thijs Verschuuren, who had previously worked in biodynamic viticulture in France’s Loire Valley, the team switched to biodynamic farming methods on 14 acres at the famous HJW Vineyard—planted in 1977—and each growing season began to compare results with another plot in the same vineyard that is farmed organically. Both parcels are hand-picked; the grapes from both are then hand-sorted and fermented with native yeast.
For the biodynamic block, it was a rough start, recalls Merwarth. “We saw an adjustment period where the vines were in transition and were out of balance initially.” Vines can take two full growing seasons to make the transition, he notes, because “they are confused as to why you have stopped mitigating all risks until they realize that you have provided them with the strength to withstand and eliminate risk factors on their own. It’s a bit like parenting.”
One of the challenges in biodynamic farming is following the astronomical calendar that lays out recommendations for planting, pruning, cultivating and other farming tasks based on the positions of the sun, moon and planets. For those who choose to strictly follow the biodynamic calendar, as the Wiemer team did for their experiments, grapes can only be harvested on “fruit days” rather than when the grower believes they are at ideal ripeness, or in advance of bad weather—not exactly easy in a region plagued by frequent rains, fungus, occasional hail and deep freezes.
Merwarth and Bynke, who are obsessive about optimal ripeness within each vineyard, struggled with this limitation. “We often pick a single block between seven and 15 times over a couple of weeks in order to capture all the nuances of flavor and get the right acid profile,” Merwath says. For example, in 2017, while the organic HJW vineyard block was picked across seven different days, the biodynamic plot was only able to be picked on two.
Yet over time, the vines began to make small adjustments and the grapes began to all ripen within a shorter timeframe. Merwarth first noticed the grapes were developing thicker skins—better for resisting mildew. The natural yeasts present in the vineyard increased dramatically, which resulted in faster native fermentations in the cellar. “As we stop caring for them, they start taking care of themselves,” Bynke says.
A dramatic discovery came in 2018, during a very challenging growing season. Black rot devastated the organically farmed HJW Vineyard. Organic treatments just weren’t strong enough to combat the fungal disease, Merwarth explains, and 90 percent of the fruit was lost. Yet in the biodynamic block, where only anti-fungal herbal “tea” preparations were used, most of the fruit was totally unaffected. “Rain was torrential; we were picking in several feet of water. Yet the fruit was impeccable,” he says. “The vines had been farmed biodynamically for four years at that point and had gained resilience, altered their growing behavior and had the ability to fight off the disease.”
Convinced of the efficacy of biodynamics, Bynke and Merwarth began converting their other parcels. The entire HJW site will receive Demeter USA certification in April 2023, and they have begun trials at Standing Stone, the neighboring estate the duo purchased in 2017, with over 40 acres of older vines. (They now own the largest collection of old vines in the Finger Lakes—by a lot.) However, he warns that biodynamics is not for the lackadaisical. “It only works if growers can commit to very sound farming, and extremely rigorous fruit selection and sorting; otherwise it can be a disaster—the risks skyrocket. All the [conventional] tools are gone.” It helps to have a big staff—since the two took ownership of Wiemer, the company has grown from four to 27 full-time employees among the winery, vineyards and nursery—to succeed with this kind of labor-intensive viticulture.
But does the biodynamically farmed plot result in more site-expressive wine? I informally sampled a range of vintages from each of the blocks with Merwarth and Bynke and immediately noticed brighter acidity in all the bottlings from the biodynamic section. In addition to having higher acidity levels and lower pH that the lab analyses indeed confirmed, the wines were also more savory and focused, and less expressively fruit-driven.
Bynke agrees and points out a distinct herbal tea note that he has come to see as another hallmark of that block. Merwarth describes it as a “distinct non-fruit undercurrent that is present in these wines—a minerality and also an herbal quality. And the acidity tends toward a more vibrant, textural feeling.”
Experiments like this take a decade to perform, but Merwarth and Bynke have more underway, particularly with Cabernet Franc. At their grapevine nursery, they have isolated four distinct Cabernet Franc clones, which they ferment, age and bottle separately. “You will soon start to see some fantastic Cabernet Franc coming out of Finger Lakes—serious, complex wines. With almost 25 years working with Cabernet Franc, we feel that we are coming to a place where variety does start defining a place.”
