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What’s the fuss about complex wines?

A wine as complex means different things to different people. Let’s clarify using recent scientific data. This is the first article of a series.

Published June 17, 2021

What makes a complex wine? The sum of its parts or their integration?

Roger asked me a question that prompted this reflection during one of my recent classes.

Do wine aroma compounds mixed together and creates an integrated aromatic profile? Or do they retain their characteristics, even though they co-exist? 

It reminded me of another question posed by Andy.

How do you describe a good wine? Because I usually can’t take it apart.

I love learning from my students their wine discoveries. I also want to help them with their struggles when describing wine aroma. 

And these two questions are challenging to answer because there is no easy answer. Complexity in wine doesn't have a formal definition. 

What is a complex wine?

According to Wang and her colleagues, the Wine and Spirit Education Trust (WSET) defines a complex wine as "having multiple flavors that span multiple clusters."

Most sensory scientists embrace Berlyne's definition that a complex product has multiple and distinct components.

But recently, Wendy Parr and colleagues reported that "Perceived harmony and balance of a wine, presumably linked to a degree of perceived integration, were linked positively to perceived complexity." Their study was on Sauvignon blanc wines.

Wine professionals also use the word complex to describe older wines, which develop tertiary aroma with aging.

What is a complex wine? 

Is it?

  • A multi-layered flavorful wine,
  • A wine imparting multiple and distinct aromas, tastes, and mouthfeels, or
  • A wine is perceived as the blend of its components and evoking one integrated perception.

Let me know your thoughts below, and learn from other readers. 

Does complexity increase with wine aging?

In this first article on the topic of wine complexity, I'm sharing results from a study conducted by Janice Wang and her team on aged Madeira wines. 

The researchers wanted to assess if perceived complexity increased with wine aging. They wondered if a complex wine was defined by its components (sometimes called depth), its evolution, or persistence in the mouth (or called length). 

Wines and Tasters

Participants evaluated 6 wines from 2 grape varieties (Tinta Negra and Malvasia) with different aging times (3, 10, or 20 years).

A group of wine experts, freshly graduated from the WSET Diploma, one of the highest wine certifications, participated in the study.


Wines were served in coded black glasses, and their order was randomized among the tasters.

The wine evaluation was three-fold.

  1. A rating of each wine on a scale anchored from not complex at all to very complex;
  2. The evaluation over 2 minutes of 8 sensory attributes (orange zest, apple, ground coffee, burnt caramel, roasted walnuts, sweet, sour, and bitter).
    Participants selected the descriptors they perceived, first during 30 seconds while the wine was still in their mouth (assessing depth) and then 90 seconds after swallowing the wine (assessing length).
  3. Participants then answered this simple question freely "what makes a wine complex?"


  • The longer the wine aged, the more complex its ratings by the wine experts.
  • Both depth and length of sensory perceptions define complexity.
    Indeed, tasters described complex wines with a higher number of sensory attributes and longer persistence in the mouth. Table 1 provides more details.
  • However, the concept of complexity didn't include how much the wine sensory profile changed over time. It's interesting because that's how I would define complexity.

Table 1 Main sensory differences perceived by the wine experts
among the six Madeira wines.

What makes a complex Madeira wine? 

It aged at least 10 years in wooden casks, has a bitter taste on the onset, along with ground coffee notes and burnt caramel, and ends on a roasted walnut aroma.

These results only pertain to this category of fortified wines and may not apply to table wines.

In the next issue:

I will explore another definition of a complex wine: A wine perceived as the blend of its components and evoking one integrated perception.

In the meantime, please share with the other readers and me what YOUR definition of a complex wine is. 

[Give your definition of a complex wine].

And feel free to add a comment below.

  • Q. J. Wang, T. Niaura, K. Kantono. (2021). How does wine ageing influence perceived complexity? Temporal-Choose-All-That-Apply (TCATA) reveals temporal drivers of complexity in experts and novices, Food Quality and Preference, Volume 92, 104230.
  • D. E. Berlyne. (1960). Conflict, Arousal, and Curiosity. Eastford, CT: Martino Fine Books.
  • W. V. Parr. (2015) Unraveling the nature of perceived complexity in wine. Practical Winery & Vineyard, January 5-8.

Categories: Tasting education, wine aroma, wine style

Isabelle Lesschaeve

Principal, Blog author, and Wine Tasting Coach

Internationally renowned wine sensory scientist, Isabelle demystifies wine tasting and helps serious wine lovers sharpen their tasting skills and tasting notes in a supportive community.

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