If Part I explored soil and terroir, Part II examines biological origin.

Wine does not come from soil alone.

It comes from a living plant.

The vine is a complex biological system continuously responding to climate, sunlight, water availability and viticultural decisions. Understanding the vine’s annual cycle is essential to understanding structure, acidity, tannins and aromatic expression.

Before the cellar, there is plant physiology.

The Vine’s Annual Cycle

Each year, the vine follows a precise biological rhythm that directly influences grape quality and wine potential.

The main stages include:

1. Bud break
2. Flowering
3. Fruit set
4. Veraison
5. Ripening
6. Harvest

Each stage affects sugar accumulation, acid retention, phenolic development and structural balance.

Wine identity is defined long before fermentation begins.

Bud Break: Establishing Seasonal Potential

Bud break marks the start of vegetative growth after winter dormancy.

Accumulated spring temperatures determine timing. Late frost events may significantly reduce yield and compromise seasonal potential.

The timeline of the vintage begins here.

Flowering and Fruit Set: Yield Determination

Flowering determines production levels.

Adverse weather can reduce fruit set and affect ripening uniformity.

While moderate yield reduction may enhance concentration, instability can disrupt balance.

Production potential is defined at this stage.

Veraison: Transition to Ripening

Veraison marks the shift from growth to ripening.

Berries change color.

Sugar accumulation accelerates.

Acidity gradually adjusts.

Phenolic compounds responsible for tannin structure and aging potential begin intensifying.

This is one of the most physiologically sensitive stages of the season.

Ripening and Harvest Timing

Harvest timing is not determined by sugar alone.

It requires balance between:

1. Sugar
2. Acidity
3. Tannins
4. Aromatic development

Harvesting too early may produce unripe tannins and sharp acidity. Harvesting too late may compromise freshness and alcohol balance.

The harvest decision defines style, structure and aging potential.

The Human Role in Viticulture

Wine quality is not accidental.

Pruning, canopy management, yield control and water management directly influence vine physiology.

Viticulture guides balance.

Winemaking refines it.

CONCLUSION

Before the cellar, there is life.

Before oak, there is biology.

Wine is the result of a carefully managed plant cycle and informed technical decisions.

Part III will explore transformation — from grape to wine.