Burgundy owes much of its global reputation to the exceptional ageing potential of its white wines. However, in a context of climate change and evolving winemaking practices, one key question arises: how is this ageing potential built, preserved, and managed?

To address it, the BIVB launched the VOLTA project in 2020, involving a network of forty Burgundian wineries and the oenological team at Vinventions. At the heart of the initiative: our scientific expertise and the Polyscan—our decision-support tool—which has supplied objective data vintage after vintage.

Polyscan: Measuring to Understand

The project’s goal was clear: obtain reliable indicators to anticipate a wine’s longevity. Polyscan met this need by measuring polyphenol levels in real time – key actors in oxidation reactions – and enabling the Tendency of Evolution test (TE). This test, similar to an air exposure test, compares a wine’s initial signal to that measured after two hours of air contact:

• TE < 100 → sensitive wine, limited ageing potential
• TE > 100 → resistant wine, strong ageing potential

This method paved the way for early and reliable classification of wines from the end of alcoholic fermentation through to bottling.

Key Findings After 5 Years of Study

1. Pre-fermentation phase: limiting polyphenol extraction

Across 150 settled juice tanks monitored, batches rich in polyphenols at juice stage consistently remained high at the end of fermentation and were more prone to oxidation. The grape’s intrinsic polyphenol content is a key factor, compounded by technical winemaking choices.

Sulphiting at harvest (a major standalone factor) and all extraction-intensive practices (mechanical harvesting, crushing, long press-filling times, lack of grape cooling) promote polyphenol extraction. Their impact is even greater when grapes are already naturally rich in polyphenols, as they further concentrate already high levels.

At this stage, all operations enhancing phenolic extraction must be controlled and, where possible, limited—particularly in years or plots where grapes exhibit naturally high levels.Such adjustments reduce the polyphenol load in musts and increase the proportion of resilient wines right from the end of fermentation.

2. Ageing phase: optimal between 6 and 9 months

Data collected during ageing on over 800 batches confirmed the critical importance of this phase. Resistance to oxidation increases between 0 and 6 months, peaks between 6 and 9 months (up to 75% resilient batches), and tends to decline beyond a year.

Three key takeaways emerged:

• Ageing on full lees promotes resistance: 80% resilient wines compared to ~50% after racking
•  Small-format new oak barrels (228 L) with light toasting enhance resilience: 75% resisistant wines
• In tank ageing, only wines initially low in polyphenols showed higher resistance (70% resistant), highlighting the importance of strict polyphenol management pre-fermentation

3. Bottle ageing: four profiles revealed

To explore the link between practices and ageing potential, forty wine batches were monitored over three years post-bottling under controlled conditions (identical closures, same total oxygen at bottling). Analyses (TE, SO₂, polyphenols) and tastings were carried out regularly throughout the 3-year bottle ageing period. Four typical wine profiles emerged:

• Sensitive/oaked: early signs of evolution, ripe fruit, stable oak notes
• Sensitive/unoaked: gradual evolution, high grape-derived polyphenols
• Resistant/unoaked: aromatic stability, fresh fruit, reductive ageing
• Resistant/oaked: minimal signs of evolution, dominant and intensifying oak character

This classification, established just six months after bottling, proved predictive of the wines’ sensory and analytical evolution over three years. These insights, combined with Polyscan TE results, provide winemakers with an early diagnostic tool for ageing potential, directly informing both technical and commercial decisions.

4. Grape Maturity: An Emerging Axis

In 2024, monitoring of 20 plots using the Polyscan’s Maturox index revealed an additional factor: harvest dates appear to influence wine ageing profiles. This link between ripeness and longevity opens new perspectives for optimizing harvest timing. Further trials are planned to confirm these initial findings.

Over five years, the VOLTA project has provided concrete answers to a crucial question for Burgundy: how can we preserve the signature longevity of great white wines in the face of today’s challenges? Results demonstrate the importance of limiting polyphenol extraction in the pre-fermentation phase, favouring ageing on full lees and light new oak, and using the Tendency of Evolution test for early prediction of longevity. To these winery-level levers, grape maturity now adds a potential vineyard-level tool. These findings—born from a unique partnership between research and practice—offer winemakers solid guidance to continue crafting wines that stand the test of time.