Farewell to Miha Istenic, the kind sparkling wine producer

In recent decades, Slovenian sparkling wine has gone from relative obscurity to international recognition. At the heart of this transformation is Miha Istenič, whose work at the family estate in Bizeljsko-Sremič has redefined both the perception of Slovenian sparkling wine abroad and the way it is produced at home. His contribution is not limited to raising quality standards, but includes the re-evaluation of indigenous varieties and the evolution of production philosophy within a traditionally conservative category.

This article is written in memory and celebration of him: Miha Istenič passed away on 3 January at the age of 61, leaving behind a decisive legacy for the sector and a profound mark on Slovenian wine culture.

Istenič's reputation was cemented in 2013 when he was named the best sparkling wine producer in Slovenia in Christy's World Encyclopedia of Champagne and Sparkling Wine. In the same context, he was listed among the twenty best sparkling wine producers outside Champagne, a recognition that brought Slovenia — and Istenič in particular — to the centre of a debate that had until then been dominated by much larger and more established wine-producing nations. These are not symbolic honours, but a reflection of consistent technical excellence and a stylistic identity that is recognisable in blind tastings and professional evaluations.

One of the most characteristic aspects of Istenič's work is his commitment to Rumeni Plavec, a native Slovenian grape variety long considered unsuitable for the production of high-quality sparkling wines. Rather than conforming to international standards based on Chardonnay and Pinot Noir, Istenič demonstrates that local grape varieties can also produce wines with character that are fully competitive on a global level. This vision is confirmed by Rare Passion 2009, a sparkling wine made from 100% Rumeni Plavec, which scored 91 points from Robert Parker's Wine Advocate: an exceptional result for an almost unknown grape variety, as well as proof that his experiments are not regional curiosities, but relevant oenological research on the international scene.

Beyond individual accolades, Istenič's most lasting legacy lies in his role as a pioneer of minimal intervention sparkling wine in Slovenia. Long before the concept became a widespread trend, he began to question the dominant emphasis on technological control, dosage and stylistic uniformity. This reflection led to the creation of the Rare line, which marked the beginning of a new production philosophy within the estate: to let the vineyard and fermentation express themselves with as little interference as possible.

The Rare sparkling wine itself is emblematic of this change. Composed of 80% Rumeni Plavec and 20% Chardonnay, it is not only stylistically distinctive, but also technically unprecedented: it is the first sparkling wine in the world to undergo four fermentation stages, a process designed to deepen its complexity while preserving its natural structure and expressiveness. Rather than eliminating irregularities, Istenič's method embraces the intrinsic variability of grapes and fermentation, challenging conventions about how sparkling wine “should” be produced.

This trend towards minimal intervention does not represent a rejection of precision or quality control. On the contrary: each stage of fermentation introduces new variables that require careful monitoring and a deep understanding of microbial activity, the structure of the base wine and its behaviour during ageing. What sets Istenič apart is the fact that this innovation does not stem from a fad, but from a coherent philosophical question: how much intervention is really necessary to produce a great sparkling wine?

Miha Istenič's influence on the Slovenian sparkling wine industry is therefore twofold. On the one hand, he demonstrates that Slovenian producers can compete with the best outside Champagne in terms of both style and critical acclaim. On the other, it expands the conceptual boundaries of what Slovenian sparkling wine can be: rooted in indigenous varieties, shaped by experimentation and guided by a sober, vineyard-focused approach.

Today, as minimal intervention, terroir-driven wines are gaining popularity globally, Istenič's work does not appear to be a response to the trend, but rather a precursor to it. His career demonstrates that innovation in wine does not require abandoning tradition, but rather questioning it. In this way, Miha Istenič has not only elevated a single estate, but has helped to redefine the identity and ambition of Slovenian sparkling wine.