Myths, Realities and Perspectives of a Long-Discarded Ingredient
Rethinking ripeness in Bordeaux
In Bordeaux, the search for ripeness has long been a central concern. Driven by an uncertain oceanic climate, it led to increasingly strict sorting practices, with the near-total exclusion of vegetal parts, including stems, in modern winemaking. But the balance has shifted. Climate change, evolving grape profiles, and demand for freshness and aromatic clarity now push the industry to question its fundamentals.
It is in this context that Derenoncourt Vignerons Consultants carried out six years of research on stems. Long dismissed, this element, when used with precision, can provide concrete answers to today’s winemaking challenges.
A full-scale study
The study, conducted under real winemaking conditions, aimed to better understand the organoleptic and analytical impact of stems. Several series of tests were carried out by Derenoncourt Vignerons Consultants teams:
- Hydro-alcoholic infusions of stems from different grape varieties and plots
- Aromatic characterization by a professional perfumer
- Targeted chemical analyses
- Comparative vinifications with and without stems
- Large-scale triangular tastings
Altogether, these data built a refined understanding, far from stereotypes, of the role stems can play in shaping a wine.
What stems change
Contrary to common belief, the color or apparent ripeness of a stem is not a relevant indicator of its potential. Its chemical composition, origin, vintage, and grape variety are what matter most.
On the aromatic side, stems release:
- C6 compounds (green, vegetal notes)
- Salicylates (peppery, camphor, fresh notes)
- Terpenes (floral, fruity, exotic notes)
Infusions revealed a wide range: lemon, dried fruit, flowers, zest… Merlot in particular showed significant aromatic richness in its stems, far greater than varieties like Pinot Noir or Grenache.
On the palate, stems play several complementary roles:
- They provide structuring tannins, useful in dry vintages or weak musts.
- They contribute to perceived sweetness, thanks to their richness in astilbin, a naturally sweet flavanol.
- They indirectly enhance aromatic freshness, even though an increase in pH is often observed.
Unlike whole-cluster fermentation (semi-carbonic), partial and targeted use of stems makes it possible to precisely control the desired balance.
A complementary tool, not a dogma
The study shows there is no universal truth about stems. Everything depends on grape variety, vintage, terroir, and the style being pursued. Stems are neither a standard to be applied everywhere, nor a nostalgic return to the past. They are one more tool in the winemaker’s toolbox, alongside barrel aging or extraction management.
Used judiciously, they can add complexity, structure, and sometimes extra roundness, without compromising the wine’s identity or sense of place.
Rediscovery in the service of taste
Beyond the technical aspect, this study encourages a reassessment of certainties, a more nuanced approach, and a reconsideration of elements long excluded on principle. It shows that progress does not always come from technological innovation, but sometimes from the smart reinterpretation of traditional knowledge.
Through this type of research, Derenoncourt Vignerons Consultants continues to explore practical, adaptable approaches in the service of balance, terroirs, and estates.
To learn more, read the article authored by Romain Bocchio with James Suckling :