With an infusion of grape leaves and fermentation, the Rheinhessen oenologist Wolfgang Schäfer develops an aromatic independent alternative to non-alcoholic wine. Connoisseurs and wine lovers are to benefit from this.
What if, instead of removing the alcohol from finished wine using expensive methods, a non-alcoholic beverage from grapevines was produced? Wolfgang Schäfer, oenologist and owner of the wine consultancy "Tropical Viticulture Consultants," has been working on this for just over two years. His concept involves an infusion of vine leaves followed by fermentation, during which alcohol is produced only in minimal amounts. Soon, a drink with aromatic independence is to emerge – as an alternative to non-alcoholic wines.
The origins of his idea date back over 25 years. The expert in viticulture in tropical regions had a project in Vietnam: back then, he had un-sprayed vine leaves produced for the oriental specialty Dolma. It is prepared in dozens of variations in more than twelve countries, including Turkey, Greece, Georgia, Croatia, Bulgaria, and Romania. The filling of rice, vegetables, or meat is wrapped in vine leaves. "To ensure the leaves grow large enough, we had to cut many shoots to the ground," he recounts. He remembers well the moment when one of his employees, looking at the dry leaves on the ground, said, "They look just like tea." Schäfer tried it out. "What came out was a very aromatic tea," he says. A drink with many tannins, similar to green tea, and – depending on the grape variety – also with its own distinct aroma. From the tea-like drink, the oenologist developed the so-called "Grape Leaf Soda," a tea from vine leaves mixed with grape juice and water, which he presented in 2017 under the name KISUU at ProWein. "The drink was quite well received, but we failed in marketing it," reports Wolfgang Schäfer.
The popular specialty Dolma in the Orient and Southeast Europe inspired Wolfgang Schäfer to work with vine leaves.
WikipediaThe idea did not let the oenologist go: "We wanted to make the whole thing even more high-quality," he describes his considerations. With Brain AG in Zwingenberg, Hesse, he found the right partner. The biotechnology company is working on the development of microorganisms as an alternative to chemical processes. During a conversation, the idea arose to jointly develop a new drink: "The task for Brain AG was to find microorganisms that ferment an infusion of vine leaves without producing alcohol."
In what steps the new drink is specifically created is Schäfer's secret. "I won't reveal any details," says Schäfer with a smile. He only reports how he regularly strolls through the vineyards with colleagues and large blue IKEA bags, harvesting hundreds of kilograms of leaves. Currently, they are still manually picked in the participating vineyards – necessarily before the first plant protection. "We also tried classic grape varieties, but interestingly, they don’t taste good. Leaves from Piwi grape varieties are much more aromatic," he has observed. The chopped leaves are then mashed with water and stirred repeatedly over a longer period. This creates an infusion, which is then pressed and sterilized into so-called kegs, small reusable stainless steel barrels for germ-free storage.
"Now we could add grape juice, but for a higher-quality product, we want to ferment it," says the beverage developer. The fermentation and a long yeast storage ensure a drastic change in flavor. "The result (see image at the top) tastes more like wine than iced tea," says Wolfgang Schäfer. Currently, initial trials with a mash fermentation are underway: "We have high hopes that a stable and exciting product will emerge from this." Because the end product is not wine but a food product, they want to work with as few additives as possible: "We have to list everything on the label." Therefore, only grape juice, which they also produce themselves, is considered for sweetening.
The vine leaves must be un-sprayed, and the vines are pruned in a special way.
Tropical Viticulture ConsultantsA hurdle in the development is the harvest of the suitable leaves. Because they must definitely be un-sprayed, only leaves from fungus-resistant grape varieties are suitable. But even these will eventually be sprayed, so the time window for a leaf harvest is limited. Additionally, the winemaker must lay the foundation with pruning in winter for the new purpose to ensure sufficient leaf mass for the harvest. However, after collecting the leaves, the vines still need enough foliage for the grapes to ripen. "By 2026, we expect to produce 100,000 bottles, and for that, we also need corresponding quantities." As a cooperation partner, Wolfgang Schäfer is working, for example, on projects like the Piwi sparkling wine project of the Rotkäppchen winery in collaboration with the EZG Goldenes Rheinhessen, for which 30 hectares of the Piwi variety Calardis blanc have been planted.
For more than two years, the development has been underway under the project name Sustainable Beverage (SUSBEV), for which the participants have invested a lot of their own money. The project received new momentum in January. With a funding program from the Ministry of Education and Research, there is now enough budget available to accelerate development. In addition, the Provadis School of International Management and Technology in Frankfurt am Main has taken over a sustainability assessment of the new drink. The Rheinhessen winemaker Eva Vollmer is also involved with the association "Future Wines" – and thus the developers have access to more Piwi vineyards. With a six-figure sum from the ministry's funding pot, the Piwi association also wants to design professional marketing. For the winemakers, this is "a fantastic win-win situation," explains Wolfgang Schäfer: "For the vine leaves, they receive money, the grapes remain healthy, they achieve high must weights – and the wine can also be sold better." Together with his business partner Hans-Peter Höhnen, he wants to produce the drink primarily on behalf of wineries: as a non-alcoholic or low-alcohol complement to their own wine portfolio.
Their goal is to officially present the prototype by the end of 2025 and to launch three different variants in white, rosé, and red in 2026. "With and without carbonation," adds Wolfgang Schäfer. For the design, he envisions a "wine aesthetic." A small bottle would push the drink into the lemonade corner, while the Tetra Pack looks "too much like iced tea" to him. And how do the first variants of the future drink taste? Many phenolic aromas, along with a bit of sake stylistics, more green than fruity, yet with a certain acidity freshness. Wolfgang Schäfer knows: "It’s hard to compare this drink with a wine. There’s still a lot of work to be done."