Catechins are natural flavonoid phenols present in grapes, skins, seeds, and even wood. In red wines they are part of the structure winemakers expect and manage. In white wines, however, excessive catechins extraction can become a silent threat.

They are directly linked to:

• Bitterness and astringency

• Browning reactions

• Aromatic instability

They are considered important contributors to oxidative reactions associated with premature aging.

Many condensed tannins are formed through the polymerization of catechins and epicatechins units. Catechins are the building blocks — highly reactive molecules that participate in oxidation reactions from the very first stages of vinification.

Modern white winemaking is largely designed around limiting phenolic extraction. This explains why many premium wineries prioritize:

• Whole-cluster pressing

• Gentle grape handling

• Careful clarification

• Limited press fractions

• Controlled oxidation strategies

• Precise SO₂ management

The objective is clear: obtain cleaner musts with lower flavonoid phenol concentrations.

One of the most interesting findings observed in white wines is the relationship between catechin concentration and oxidation stability.

Wines below approximately 10 mg/L catechins tend to:

• Maintain a more stable color

• Resist browning

• Preserve aromatic freshness longer

• Show lower sensory astringency

Above this level, oxidative reactions accelerate significantly, especially in wines stored with low dissolved SO₂.

The result? Notes associated with oxidative aging:

• Honey

• Nuts

• Toasted bread

• Cooked vegetables

• Dried herbs

• Mushrooms

Sometimes long before the wine should show any sign of evolution.

Traditionally, HPLC has been the reference technique for catechins analysis. While extremely accurate, it is often impractical for routine winery operations:

• Expensive instrumentation

• Complex interpretation

• Slow turnaround times

For real production decisions, wineries need something faster. That is where the DAC method (4-dimethylamino-cinnamaldehyde) becomes especially valuable.

This method:

• Specifically reacts with flavonoid catechins

• Measures directly at 640 nm

• Has shown strong correlation with HPLC measurements in validation studies

• Avoids interference from sugars, alcohol, SO₂, or ascorbic acid

Most importantly, it provides actionable information quickly enough to influence:

• Pressing decisions

• Juice fraction selection

• Clarification strategy

• Oxidation management

• SO₂ timing