Complexity — Multiple Aromas and Flavors Evolving in the Glass; Hallmark of Fine Wine

Complexity in wine refers to the presence of multiple, intertwining aromas and flavors that coexist and evolve within a single glass. The Wine and Spirit Education Trust defines a complex wine as one whose flavors span multiple clusters, or that draws on a combination of primary aromas from the grape, secondary aromas from winemaking, and tertiary aromas that develop with aging. Unlike a straightforward wine that presents a single dominant impression, a complex wine reveals successive layers: bright primary fruit gives way to secondary notes of oak, spice, or lactic character, and with time, tertiary characteristics such as leather, truffle, tobacco, or dried fruit emerge. Complexity is one of the four formal quality criteria in the WSET Systematic Approach to Tasting, under the BLIC framework.

• Formally defined by WSET as flavors spanning multiple clusters, or arising from primary, secondary, and tertiary aroma sources
• Distinct from mere concentration: a high-extract wine can be one-dimensional, while a more restrained wine can be extraordinarily complex
• Distinct from a flawed or muddled wine: genuine complexity is harmonious and evolving, not discordant or confused
• Central to the European fine wine tradition, particularly in regions like Burgundy, Barolo, and Bordeaux, where terroir and time are considered essential inputs

Complexity is one of the primary determinants of aging potential and what distinguishes fine wine from commodity wine. In the WSET quality framework, a wine that achieves all four BLIC criteria — Balance, Length, Intensity, and Complexity — is rated outstanding. Wines lacking complexity tend to plateau quickly; their fruit fades without being replaced by anything of interest. Conversely, wines with latent structural complexity continue to reveal new dimensions over years or decades in the cellar. As wines age, tannins soften, fruit intensity decreases, and complexity often increases as tertiary aromas develop. For collectors, sommeliers, and students preparing for examinations, understanding complexity is foundational to quality assessment.

• An outstanding rating in the WSET SAT requires all four BLIC elements: Balance, Length, Intensity, and Complexity
• Aging potential depends on complexity: wines with multiple flavor layers at release are more likely to reward cellaring than simple, fruit-forward styles
• Tertiary aromas — leather, truffle, tobacco, dried fruit, earth — only emerge in wines with the structural depth and concentration to develop them
• Complexity signals the convergence of grape genetics, terroir, skilled winemaking, and sufficient time

Identifying complexity is a systematic practice. Allow the wine at least ten minutes in the glass before initial assessment, then nose it in stages. The first nosing captures primary aromas — fruit, floral, and herbal notes derived directly from the grape variety. After five or more minutes, secondary aromas become more evident: buttery notes from malolactic fermentation, vanilla and toast from oak, biscuit or bread from lees contact. In older or well-aged wines, tertiary notes emerge: leather, tobacco, mushroom, earth, dried fruit, or petrol in aged Riesling. On the palate, a complex wine shows flavor evolution from the attack through the mid-palate to the finish; if the dominant impression remains identical across all three phases, simplicity prevails. The presence of contrasting aromatic families simultaneously — dark fruit alongside floral notes alongside mineral character — signals genuine structural complexity.

• Nose in stages: primary (fruit and floral) leads to secondary (spice, oak, lactic) leads to tertiary (leather, earth, tobacco) with time in the glass
• Monitor the palate arc from attack to mid-palate to finish: does the flavor profile shift and develop, or remain static?
• Look for aromatic contrast: multiple distinct scent families coexisting is a reliable marker of complexity
• Decanting or extended airing can reveal complexity in younger wines; simple wines show little evolution, while complex wines transform over 30 to 90 minutes

Barolo from Giacomo Conterno represents Northern Italian complexity in its most traditional form. Located in Monforte d'Alba, the estate produces its flagship Monfortino Riserva with a minimum of seven years aging in large Slavonian oak botti, resulting in wines that unfold notes of tar, rose, dried cherry, leather, and licorice over decades. In Châteauneuf-du-Pape, Domaine du Vieux Télégraphe, founded in 1898 by Hippolyte Brunier on the La Crau plateau, produces Grenache-dominant red wines aged 20 to 22 months in French oak foudres; these wines integrate garrigue, dark berry, spice, and mineral character drawn from the famous rounded galet stones of the plateau. Aged Mosel Riesling, with its remarkably low alcohol of 7.5 to 11.5% ABV, shows that complexity is independent of body or power, developing citrus, slate, and distinctive petrol or mineral notes over time. Red Burgundy from serious producers demonstrates how Pinot Noir can evolve from fresh red fruit and floral primary aromas into a tertiary bouquet of forest floor, mushroom, and dried rose with bottle age.

• Giacomo Conterno Monfortino: minimum seven years in large Slavonian oak botti; Nebbiolo tertiary profile of tar, rose, leather, and dried cherry
• Domaine du Vieux Télégraphe: La Crau plateau terroir of galets and molasse soils; 20 to 22 months in French oak foudres; Grenache-dominant blends of garrigue, dark fruit, and mineral character
• Mosel Riesling: 7.5 to 11.5% ABV yet capable of profound complexity; lime, mineral, and petrol tertiary notes develop with age
• Great Burgundy: Pinot Noir transitions from primary red fruit and violet to tertiary forest floor, mushroom, and dried flower bouquet over years in bottle

Complexity is related to, but distinct from, several other wine quality concepts. Concentration and power describe the weight and extract of a wine, but a highly concentrated wine can be simple if it offers only one-dimensional dark fruit. Balance — harmony between acidity, tannin, alcohol, fruit, and sweetness — provides the framework within which complexity can be perceived; an unbalanced wine can mask its own layers. Intensity refers to the strength and expressiveness of aromas and flavors, not their diversity. Length measures how long flavors persist on the finish after swallowing. All four together form BLIC. Structure (tannin and acidity) supports complexity by enabling aging, but does not create it; complexity requires actual aromatic and flavor diversity, not just firm structure.

• Structure vs. Complexity: high tannin provides aging potential but does not guarantee multiple flavor dimensions
• Concentration vs. Complexity: high extract can be one-note; complexity requires contrasting aromatic families
• Balance enables complexity: without harmony between structural elements, layered flavors are harder to perceive
• Intensity vs. Complexity: a pronounced wine can still be simple; complexity requires range and variety, not just strength

Complexity emerges from the convergence of several inputs. Grape variety genetics play a role: Nebbiolo, Pinot Noir, and Riesling are recognized for their capacity to develop aromatic range. Terroir contributes through soil minerality and microclimate; the galet stones and molasse soils of Châteauneuf-du-Pape's La Crau plateau, or the steep slate slopes of the Mosel, leave distinct impressions on the finished wine. Winemaking decisions matter: malolactic fermentation adds secondary lactic and butter notes; extended lees contact during sur lie aging produces biscuit and yeast autolysis characters in sparkling wines and white Burgundy; oak aging contributes vanilla, spice, and toast as secondary aromas while facilitating micro-oxygenation. Extended bottle aging allows phenolic polymerization and the emergence of tertiary aromas. Yield management concentrates phenolic diversity, and minimal-intervention approaches in the cellar can preserve aromatic nuance that heavy-handed processing would eliminate.

• Malolactic fermentation adds secondary lactic, cream, and butter dimensions beyond primary fruit aromas
• Oak aging introduces vanilla, toast, spice, and cedar as secondary aromas while micro-oxygenation supports long-term development
• Extended bottle aging converts primary and secondary aromas into tertiary ones such as leather, tobacco, mushroom, and dried fruit
• Terroir minerality, soil composition, and microclimate provide the raw aromatic palette from which complexity is built