Secondary Aromas

What are secondary aromas?

Secondary aromas (also called winemaking-derived aromas) are aromas that do not originate from the grape itself but instead develop during fermentation and winemaking. They are the result of cellar processes such as alcoholic fermentation, lees contact, malolactic fermentation, or ageing in barrique.

While primary aromas reflect the character of the grape variety, secondary aromas are the winemaker's signature and the expression of their oenological decisions.

How do secondary aromas develop?

Secondary aromas arise through various processes during vinification:

Alcoholic fermentation

During fermentation, yeasts convert sugar into alcohol and carbon dioxide. As by-products, numerous aromatic compounds are formed:

• Esters: Fruity aromas (banana, pear, apple)
• Phenylethanol: Floral, rose-like notes
• Higher alcohols: Complex, spicy aromas

Fermentation temperature plays a major role: cool fermentation (15–18°C) in white wine preserves the fruit, while warmer fermentation (22–28°C) in red wine produces spicier notes.

Malolactic fermentation

Malolactic fermentation converts sharp malic acid into softer lactic acid, producing characteristic aromas in the process:

• Butter: Through diacetyl
• Cream, milk: Creamy, milky notes
• Yoghurt: Slightly tart and creamy
• Hazelnut: Nutty components

Lees contact (Sur Lie)

Lees ageing allows the wine to mature on dead yeast cells. The yeast gradually releases compounds (autolysis):

• Brioche, fresh bread: Typical of Champagne
• Yeast, dough: Direct yeast notes
• Creamy, buttery: Through mannoproteins
• Nutty: Almond, hazelnut

Barrel ageing

Ageing in barrique or other oak vessels is one of the most important sources of secondary aromas:

• Vanilla: Vanillin from the wood
• Toast, roasted notes: From the toasting of the barrels
• Spices: Clove, cinnamon, nutmeg
• Coconut: Especially in American oak
• Smoke, coffee, chocolate: With heavier toasting

Typical secondary aromas

Secondary aromas can be grouped into categories:

Yeast aromas

• Brioche, bread, pastry
• Yeast, dough
• Biscuit, croissant

Dairy products

• Butter (diacetyl)
• Cream, buttermilk
• Yoghurt
• Fresh cheese

Wood and spice

• Vanilla
• Toast, roasted notes
• Cinnamon, clove, nutmeg
• Coconut
• Cedarwood

Roasted and toast aromas

• Coffee, espresso
• Cocoa, chocolate
• Caramel
• Smoke
• Roasted nuts

Nutty aromas

• Almond
• Hazelnut
• Walnut
• Cashew

Secondary aromas in different wines

Chardonnay

Chardonnay is the prime example of secondary aromas:

Chablis (stainless steel): Minimal secondary aromas, focus on primary fruit and minerality

Burgundy Chardonnay: Intense secondary aromas from barrique, lees ageing, and malo — brioche, butter, hazelnut, vanilla

Californian Chardonnay: Often strongly pronounced butter (malo) and vanilla (barrique)

Champagne and sparkling wines

Secondary aromas are essential for the character:

• Brioche, toast: From extended lees ageing (years)
• Pastry, biscuit: In prestige cuvées
• Butter: When malolactic fermentation has been carried out

Red wines

Barolo: Liquorice, tar, dried herbs from long ageing in large wooden vessels

Rioja: Intense vanilla and coconut from American oak, toast from extended barrel ageing

Bordeaux: Cedarwood, spice, toast from French barrique

Burgundy Pinot Noir: Subtle spice notes, forest floor, restrained oak

Primary, secondary, and tertiary aromas

The three aroma levels in wine:

In young wines, primary and secondary aromas dominate. With ageing, tertiary aromas develop while primary fruit fades.

Balance and wine quality

The balance between primary and secondary aromas is crucial:

Good balance: Secondary aromas complement and support the primary fruit without overwhelming it. The wine shows complexity while retaining its identity.

Out of balance:

• Over-oaked: Vanilla and toast dominate, the fruit is barely perceptible
• Too buttery: Excessive diacetyl masks varietal typicity
• Too yeasty: Exaggerated brioche notes seem one-dimensional

Modern trends

In recent years the trend has moved towards more subtle secondary aromas:

• Fewer new barriques, more used barrels
• Larger vessels instead of small barriques
• Shorter ageing periods
• More focus on terroir and primary fruit
• Less malolactic fermentation for white wines

This is a reaction to the over-oaked, technically dominated wines of the 1990s and 2000s.

Identifying secondary aromas

When tasting, ask yourself:

Nose:

• Do I smell butter, cream, or dairy products? → Malo
• Are there brioche, bread, or yeasty notes? → Lees ageing
• Do I detect vanilla, toast, or spice? → Barrique
• How pronounced are the oak aromas?

Palate:

• Is the texture creamy and round? → Malo or lees ageing
• Can I taste oak tannins? → Barrique
• Is the acidity soft? → Malolactic fermentation

Practical tip

If you prefer fruity, varietally expressive wines, choose wines with minimal secondary aromas:

• Stainless steel ageing instead of barrique
• No malolactic fermentation
• Short or no lees ageing
• Examples: Riesling, Sauvignon Blanc, Beaujolais

If you enjoy complex, creamy wines with depth, look for wines with pronounced secondary aromas:

• Barrel ageing
• Malolactic fermentation
• Extended lees contact
• Examples: Burgundy Chardonnay, Rioja Reserva, Champagne

Secondary aromas are not a quality marker per se — what matters is the balance and whether they suit the style of the wine. An over-oaked wine is not better than a fresh stainless-steel wine, just different.