Sometimes referred to as hybrids, interspecific grape varieties are emerging in Belgium as the royal way to an eco-responsible vineyard that produces singular wines representative of a unique terroir. The owner of Château de Bioul, in Wallonia, has taken on this bold mission.

By Frédéric Arnould, DIP WSET

Everyone knows Merlot, Riesling, Cabernet Sauvignon and Pinot Noir. But what about Solaris, Cabernet Cortis and Johanniter? These grape varieties are the result of natural cross-fertilization. We’re not talking GMOs here, but crosses between European, American and even Asian varieties to produce these so-called interspecific grape varieties.

One of the great advantages of creating these varieties? They are resistant to those dreaded diseases that affect so-called traditional vineyards (planted with Merlot, Cabernet, Riesling and others): mildew, powdery mildew and botrytis. This makes them “cleaner” vines, as there’s technically no need to spray them with herbicides, pesticides and other chemical fungicides in the vineyard. What’s more, their adaptation to the northern climate is a logical choice.

Interspecifics, the choice of the future

This is precisely the choice made by Vanessa Vaxelaire who cultivates vines at Château de Bioul, an estate whose origins date back to the 11th century in Wallonia, the French-speaking part of Belgium. I think Belgium is the first country in the world that could boast a clean vineyard,” she says. These grape varieties really get the job done, and more and more of us are moving in this direction, for which I’m something of a standard-bearer.”

Vanessa Vaxelaire

Vanessa Vaxelaire

In French-speaking Belgium, she is fortunately not alone in this. But her authoritative arguments are most convincing. “The first thing is that, ecologically speaking, there’s no need for treatment. You can always tell me that perhaps resistance will disappear, but in the meantime, it works well.”

As a result, the 11 hectares planted at Château de Bioul in clay-limestone soils crossed by a slab of carboniferous schist are certified organic. The vineyard, located in the village, features channelled grassing, low yields and beehives in the heart of the vines, with perches for birds of prey to enhance biodiversity. Vanessa Vaxelaire has gone even further, following biodynamic precepts such as cones filled with cow dung, but with one exception.

“I don’t have a biodynamic label because I don’t want to use indigenous yeasts,” she says, “but I have, and I think it’s far too random because the yeast lives, so I don’t want to have to wonder what we’re going to do if things go wrong.”

Château de Bioul in Wallonia, Belgium

Château de Bioul in Wallonia, Belgium

A question of identity

The outspoken Belgian winemaker is an advocate of interspecific grape varieties, because she firmly believes that her wine country must lead the way in originality. “We have our own identity”, proclaims the chatelaine.

“I just don’t want Belgium to take the turn that Napa Valley is after, which is sometimes to make nothing but copies of French wines. And so, while I completely agree that some Belgian wineries are doing very nice things, I’m not criticizing those who choose to do so. But I’d be sad if everyone jumped into that breach.” – Vanessa Vaxelaire, Château de Bioul

Because these interspecifics make for more environmentally-friendly viticulture and fruit-growing, they give the Walloon vineyards a particularity that the winegrowers of the Sambre et Meuse region should capitalize on.

“At first, I asked myself the same questions. Are we going to be able to make great wines for the big competitions? Of course, when you bring interspecific grape varieties to the market, there’s obviously a certain amount of adaptation time for sommeliers.

Convince now

Vanessa Vaxelaire is aware that more needs to be done to educate professionals and consumers alike. “But in 40 years’ time, how happy we’ll be to have a Belgium with the authentic grape varieties that are ours.”

The battle is not yet won among his own profession, especially on the Flemish side, more fond of traditional grape varieties.

“The most mind-boggling thing I hear is owners coming up to me and saying yes, but I’m going to plant Vitis vinifera grapes because I want to do great things with them.”

“It’s as if the grape variety, or the wine, depends on the grape variety. It has nothing to do with that, it’s the winemaker who makes great wines, and as I tell them, there will be as many identities as there are winemakers.” – Vanessa Vaxelaire, Château de Bioul

The urgency of convincing one’s peers now is essential, insists the Walloon winemaker, because once the vineyard is planted, it’s too late. People have the impression that Belgium is the new Eldorado for wine, but frankly, once you’re in, it’s hard,” she admits. I’m not at all saying that everything is enchanting and that all the years are beautiful and blah blah blah, but if someone wants to plant interspecifics, I think it’s great for the future.”

When the Vaxelaire family planted vines a dozen years ago, there were just 200 hectares of vineyards in Belgium. Today, the figure is 800 hectares. “It’s skyrocketing and I don’t think it’s going to stop just yet. We’re not going to have vines everywhere, but it’s going to grow even more,” explains Vanessa, who sees the growing role of interspecifics, particularly in Wallonia, where plots are larger than in Flanders.

Belgian vineyards (2022)

259 winegrowers, amateurs and professionals

3 million liters bottled Previous production record dates back to 2018, with 2 million liters produced

Supermarkets get in on the act

Belgian retail giant Colruyt has decided to plant over 20,000 vines in the province of Hainaut. The grape varieties planted are muscaris, souvignier gris and johanniter. Next year, solaris, cabernet noir, carbernet jura and pinot kors will be planted. Colruyt hopes to fill 70,000 bottles of white, rosé and red wine.

Wines made from interspecific grapes at the Château de Bioul

Wines made from interspecific grapes at the Château de Bioul

The first appellation of its kind in the world?

Until now, Château de Bioul wines have been part of the vast “Côtes de Sambre et Meuse” appellation, but this will soon change to better reflect the typicity of the region’s vineyards, which have chosen the path of interspecific grape varieties. “Appellations were born in the beginning because we needed an appellation to be able to call ourselves château, to be able to enter a wine world. We created the Côtes de Sambre et Meuse appellation because, at the time, it covered all Walloon wines and included all the grape varieties from all over the world. Today, with the diversity of what is becoming established, this appellation is no longer relevant.”

And so the “Terres Vivants de Meuse” appellation was born. “In our appellation, we will group together all those who have planted in the Meuse valley, all the organic interspecifics. We have a strong identity of our own, and we may be the first appellation in the world to be interspecific.

A historic milestone, but there’s no question of a straitjacket for the producers who would be part of this new label. “We’re busy creating the next 40 years of the future of wine in Belgium. It’s very restrictive in terms of the Meuse organic interspecifics with our requirements, but in terms of technique, we’re going to leave a lot of freedom, because we want winemakers to be able to express themselves as they see fit.”

“We’re going to try not to legislate too much in terms of frameworks that have held us back, because we’re all a bit crazy. What we need is for consumers who buy ‘Terre vivante de Meuse’ to be sure that it’s organic.” – Vanessa Vaxelaire

Some interspecifics

Johanniter: variety with Riesling and FR589-54 (pinot gris x chasselas) as parents.

Solaris: a cross between merzling and another cross called GM6493 (muscat ottonel x seperavi severnyi).

Cabernet cortis: a cross between cabernet sauvignon x solaris

Bronner: a cross of merzling x geisenheim 6494

Brut de BioulBrut de Bioul, Crémant Blanc de Blanc Brut

Vinified with bronner and johanniter grapes, this lively, bracing sparkling wine has hints of dry riesling. Aged on laths for at least 9 months, this crémant with its fine, gourmet bubbles is a mouth-waterer, with a certain salinity on the finish. A perfect companion for tapas and aperitifs.

Mossiat -RéserveMossiat Réserve

This white is aged for 9 months in concrete egg vats and, we’re told, is lulled by musical waves. One of the estate’s most interesting wines, it’s worthy of a gastronomic experience based on fish and shellfish. The singular vegetal notes are a perfect match, with aromas of elderflower, rhubarb and mango.

Cortil BracoCortil Braco

A sign that, while bubbles and whites have the lion’s share of importance in Belgian vineyards, Château de Bioul dares to venture into red production with this blend of Cabernet Noir, Pinotin and Cabernet Jura. Promising with its mineral accents, this fine bistro red will pair perfectly with a dish of cochonnailles, or why not with some sausages and chicken drumsticks on the barbecue.

Journalist and wine writer, Frederic Arnould is a 2014 WSET Diploma graduate. Since then he travelled extensively throughout the planet to better know wine. He is also a wine judge at the Concours Mondial de Bruxelles.