How does the weather influence the quality of a wine?

The impact of climate on vintages: how does weather influence wine quality ?

Every year, nature leaves its mark on the vineyards. Behind the label of a wine, the vintage (year of harvest) plays a major role in the product's identity. And while some terroirs benefit from regular conditions, the majority of wine-growing regions are subject to climatic variations temperature, sunshine, rain, frost or drought. All these factors influence the quality, structure, maturity and ageing potential of a wine. Here's how the weather shapes a vintage.

1. What is a vintage ?

The vintage refers to thegrape harvest year. It therefore reflects the climatic conditions of that period, from flowering to harvest. Unlike a multi-millennium blend, a vintage wine captures the exact imprint of the wine year.

2. The major climatic stages of a wine cycle

Each phase of the vine cycle is influenced by the weather. These events determine grape quality, which means wine:

a. Spring (March to May)

• Key to flowering and fruit set.

• Major hazards : late frosts, rains during flowering → drop in yield, coulure.

b. Summer (June to August)

• Phase ripening and veraison (change in berry color).

• Need: warmth, sun.

• Risks : drought, heatwave, hailstorms.

c. Autumn (September to October)

• Period of harvest weather influences final maturity.

• Risks: heavy rains, grey rot, loss of sugar/acidity balance.

3. Climatic impact on wine quality

4. A few emblematic examples

• Bordeaux 2005, 2010, 2016 warm, well-balanced years → powerful, ageworthy wines.

• Burgundy 2014 fresh, taut vintage → great aromatic finesse, good freshness.

• Rhone Valley 2003 extreme heatwave → sunny, sometimes unbalanced wines.

• Alsace 2010 ideal conditions for whites → controlled acidity, superb evolution.

So, with equal terroir, two vintages can produce radically different wines, the result is a wine of great style and ageing potential.

5. Climate change and its impact on recent vintages

With the global warming, we observe :

• Earlier and earlier harvests,

• A higher alcohol content,

• A lower acidity in certain grape varieties,

• A narrowing of the gap between "large" and "small" vintages thanks to regular hot summers.

But it also comes with new challenges for winegrowers :

• Managing freshness in whites,

• Adapt pruning and shading practices,

• Anticipate extreme events (hail, late frost, drought).

6. And what about the consumer? How can you take this into account in your cellar ?

a. Choosing the right vintages for ageing

Some vintages are built to last. It is essential to take this into account when building your cellar, especially for :

• The great Bordeaux and Burgundy reds,

• Sweet wines (which depend on autumn mists),

• Vintage champagnes.

b. Use a cellar suitable for ageing

Once in the cellar, the wine must be kept under stable conditions :

• Constant temperature (12-14°C),

• Controlled humidity (60-75%),

• Protection against light and vibration.

Ageing cellars Climadiff provide the optimum environment for the best vintages to express their full potential their full potential.

Conclusion

Every vintage tells a climatic story. From spring rain to autumn sunshine, everything influences the quality of the grapes and therefore the profile of the wine. For discerning wine-lovers, tracking vintages not only helps to better bottle selection, but alsoanticipate their evolution. Provided, of course, that they are kept in a perfectly controlled cellar.