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Ribolla, Rebula
Winemakers cross borders to define a variety

Once favored by the nobility of Venice, ribolla gialla is now the focus of producers on both sides of the Italian/Slovenian border.

Ribolla gialla, also called rebula Ribolla gialla, also called rebula
Ribolla gialla (“yellow ribolla”) is native to the hills around Gorizia, a town in the far northeast of Italy that lies on the border with Slovenia. Ribolla was long considered one of the region’s greatest wines, with records dating back to the 13th century indicating its value among the Venetian nobility. But its identity has been split along shifting political borders. Gorizia belonged to the Austrian empire until it was annexed by Italy after World War I. After the Second World War, in what was then Yugoslavia (now Slovenia), the town of Nova Gorica (“new Gorizia”) grew up just across the border. The vine-covered hills that surround these towns became known as Collio Goriziano on the Italian side of the border (often simplified to Collio), and Goriska Brda on the Slovenian side.

Despite the political divisions of the last century, Brda and Collio shared the same climate, soil types and grape varieties, including ribolla. During the Cold War years, Marshal Tito’s Yugoslavia installed border stations that rigorously enforced separation from the west. Producers in Brda, with more than three quarters of the Collio Goriziano’s 21,000 vineyard acres, were forced to sell their grapes to the local cooperative winery. By the time Slovenia declared independence in 1991 and joined the European Union in 2004, Brda’s wine industry lagged behind that of its Italian counterpart. 

Brda vineyards Brda vineyards

Now, producers on both sides of the border are eager to promote their region as the home of a variety that’s called ribolla gialla in Collio, and rebula in Brda. Toward the end of August, 13 local winemakers convened with a group of international sommeliers and wine journalists in the Brda town of Dobrovo for the First International Rebula Masterclass, co-sponsored by producers from both sides of the border.
Vila Vipolze in Dobrovo, Slovenia; site of the First International Rebula Masterclass, August 2017 Vila Vipolze in Dobrovo, Slovenia; site of the First International Rebula Masterclass, August 2017

Dr. Denis Rusjan, a terroir specialist at the University of Ljubljana, explained that ribolla performs best in hilltop vineyards with high concentrations of flysch, an ochre-hued sedimentary soil with marine origins. Called ponca in Collio and opoka in Brda, it consists of alternating layers of sand, sandstone and marl. The mix is less fertile than the heavier clay soils found at lower elevations, and that low fertility helps control ribolla’s natural vigor.

Brda’s opoka soil shows layers of sand, sandstone and marl. Brda’s opoka soil shows layers of sand, sandstone and marl.

Vertical exposure of opoka soil. Matjaž Četrtič of Ferdinand winery demonstrates the soil’s friability. Vertical exposure of opoka soil. Matjaž Četrtič of Ferdinand winery demonstrates the soil’s friability.

Hail-damaged ribolla clusters Hail-damaged ribolla clusters


Brda’s hilltop vineyards can reach elevations of 800 feet, allowing the breezes that sweep up from the Adriatic to ventilate the bunches and preserve acidity in the grapes. Those hilltop exposures also leave ribolla vines exposed to the region’s hailstorms, one of which hit a few days before the masterclass.

The steep slopes of Brda and Collio call for hand harvesting, which elevates production costs. You can find inexpensive versions of ribolla, but they often come from lower, flatter areas in Friuli, where fertile soils can lead to wines that lack the concentration and textural complexity of ribolla grown in opoka.

The wines poured at the masterclass all came from grapes grown in opoka soils, presented in three flights based on variations in production methods. The first set of wines were made in a “fresh” style, vinified primarily in stainless steel tanks with skin contact ranging from a few hours to a couple of days. Dolfo’s 2016 Rebula provided a good example; at 12.5 percent alcohol, it was light and zippy, with floral scents and refreshing flavors of quince, lemon and white pepper.

The next group included wines from four different vintages, made with fruit from older vines, macerated on the skins for up to one week and aged in oak barrels of varying sizes for between eight months and two years, in contact with the lees. Youthful versions like Marjan Simčič’s 2014 Rebula Opoka retained notes of fresh green apple and citrus, yet needed time to absorb its toasty barrel tones; a 2007 from Ferdinand—the Rebula Époka— highlighted the longevity possible with barrel-aged versions, the rich, smoke-tinged wine layered with flavors of baked apple and lemon meringue.

A final flight showed ribolla in an entirely different light, focusing on wines made with long skin macerations, a style pioneered by Collio’s Josko Gravner and Stanko Radikon. In varying shades of orange, these skin-macerated wines offered a wide range of scents and flavors, from orange peel, chamomile and honey to white mushroom and green olive. Long fermentations with the grape skins require fully ripe skins to avoid bitter flavors, so vintners typically harvest the grapes later, resulting in alcohol levels of up to 14 percent. Higher alcohol contents lend a weighty warmth to the wines, while tannins from the skins create a dense, almost chewy texture. Radikon’s 2004 Ribolla Gialla stayed on the skins for three months, developing a deep amber hue and flavors of mandarin orange rind mingle with notes of chamomile tea and salty capers. Notes of mint and white pepper brighten the truffled earthiness of Gravner’s 2009 Ribolla Gialla, a savory wine that rested on the skins in amphorae for more than five months.

Skin-fermented ribolla wines Skin-fermented ribolla wines
“Orange” wines have become somewhat trendy in the US market, and the skin-fermented ribollas of Gravner and Radikon have gained a limited yet enthusiastic following among sommeliers and natural wine fans. But other styles of ribolla, like the fresh and zesty versions and the oak-fermented wines, have yet to make big inroads with American wine drinkers who are not widely familiar with the variety. Change may come from an unexpected quarter, as a handful of California wineries like Arnot-Roberts, Forlorn Hope and Matthiasson have begun bottling wines from ribolla gialla. Those California wines see varying degrees of skin contact, reflecting the diverse ways the variety is treated in its native region.

This is a W&S web exclusive feature.
photos of ribolla gialla, Brda masterclass and Brda vineyards by ZOSO – Damijan Simčič