Stale Wine Aroma: What Does It Mean?

A wine's aroma is one of the most intriguing and passion-inducing components of wine appreciation. A wine's aroma, often called its nose or bouquet, is assessed by swirling the wine and inhaling deeply through the nose. The intensity of a wine's aroma can be described as weak, moderate, aromatic, or powerful. A wine's development indicates its maturity; youthful wines tend to have fresher aromas that lean towards ripe, fresh fruit, while older wines develop new aromas, such as mushrooms, truffles, earth, tobacco, and coffee. A stale aroma in wine is considered an off aroma or flaw. Common flaws in wine include corked wine (TCA), Brettanomyces (Brett), reduction, and oxidation. A corked wine is contaminated with TCA, creating a musty aroma that masks the normal wine aromas and flavours. Brett can give wine a smokey aroma, but on the other end of the spectrum, it can smell like Band-Aids and antiseptic. Reduction can lead to funky aromas, such as a roasted, sulfur aroma, while oxidation can cause a wine's character to flatten, resembling other oxidised wines.

The wine's nose or bouquet

The nose or bouquet is assessed by swirling the wine in a glass to volatilize particles and enhance their interaction with oxygen, thereby intensifying the aromas. This technique, practised by both professionals and enthusiasts, involves swirling the wine and then bringing the glass close to the nose to inhale the diverse and nuanced scents. The swirling motion can be initially practised with water, and it is recommended to use proper wine glasses with a tapered design to concentrate the aromas effectively.

The nose or bouquet of a wine encompasses a range of characteristics, including intensity, development, and specific aromas. The intensity refers to the strength of the aroma, ranging from subtle to powerful, with great wines often exhibiting an aromatic and intense bouquet. The development reflects the maturity of the wine, indicating whether it is youthful or aged. Youthful wines tend to showcase fresh, ripe fruit aromas with hints of spice or oak, while older wines develop more intricate scents like mushrooms, truffles, tobacco, and coffee.

The specific aromas found in the wine's nose or bouquet are diverse and varied. They can include red fruits like raspberry and strawberry, melon, spices, tobacco, chocolate, flowers, and even unconventional notes like candy. These aromas derive from the complexity of grape flavours and evolve during the wine-making process and ageing. It is worth noting that the specific aromas identified can be highly subjective, as individuals may have unique associations and experiences with different scents.

Additionally, it is important to distinguish between "on" and "off" aromas. "On" aromas refer to the desirable scents that enhance the wine's character, such as fruity, floral, spicy, or earthy notes. On the other hand, "off" aromas indicate flaws or negative attributes. These can include cork taint (TCA), characterised by a musty, mouldy aroma, or the presence of Brettanomyces (Brett), a fungus that can impart smoky or barnyard-like scents in small amounts but can be overpowering in higher concentrations.

Understanding and describing the wine's nose or bouquet is a captivating aspect of wine appreciation. It involves exploring the intricate interplay of scents that evolve from the grapes, the wine-making process, and the ageing of the wine. By taking the time to swirl, sniff, and savour these aromas, wine enthusiasts can unlock a whole new dimension of enjoyment and appreciation for the complex world of wine.

Primary, secondary and tertiary aromas

A stale aroma in wine is usually indicative of a wine fault. The aroma of wine is an important aspect of wine tasting, and wine is often smelled before tasting to identify its components. Wine has three levels of aromas and flavours that evolve over time: primary, secondary, and tertiary.

Primary Aromas

Primary aromas are those that come from the grape variety itself. They are most obvious in young wines and are often what sparks interest in wine drinkers. These aromas are typically fruity, floral, or herbaceous, and can include scents of black, red, or dried fruit in red wines, and green apples, citrus, or tropical fruits in white wines. Some wines may also exhibit earthy qualities like stone or mineral, depending on the soil type.

Secondary Aromas

Secondary aromas are derived from the winemaking processes of fermentation and aging. These can include biscuit, yeasty, buttery, or creamy notes, as well as characteristics imparted by oak aging, such as vanilla, clove, smoke, coconut, or coffee.

Tertiary Aromas

Tertiary aromas develop as the wine ages in an ideal environment. In red wines, fresh ripe fruit transforms into stewed or dried fruit, and tertiary aromas of tobacco, earth, and mushroom may emerge. In white wines, dried apricot, orange marmalade, nutty, or honey notes may develop, as well as complex spice components.

It is important to note that wines with tertiary aromas are not necessarily better than those with primary and secondary aromas, as most wines are meant to be consumed young and fresh. Additionally, the perception of aromas is subjective, and different individuals may describe and perceive aromas differently based on their unique experiences and sensitivity to certain aromatic compounds.

Off aromas or flaws

"Off" aromas or flaws refer to undesirable scents in wine that can be caused by various factors, including improper handling, ageing, or contamination. Here are some common types of off-aromas and their possible causes:

• Corked Wine (TCA): This flaw is caused by contamination with TCA (2,4,6-Trichloroanisole), often due to certain types of airborne fungi infesting corks. The wine takes on a musty aroma, reminiscent of wet newspaper, cardboard, or mouldy basements.
• Brettanomyces (Brett): This flaw is caused by the Brettanomyces yeast, often resulting in a "barnyardy" aroma that some may find appealing in small amounts. However, in more severe cases, it can smell like Band-Aids, antiseptic, manure, or rancid cheese.
• Reduction: Wines with minimal oxygen exposure can undergo a chemical process called reduction, leading to "funky" aromas such as roasted sulphur or rotting vegetation.
• Oxidation: Opposite to reduction, oxidation occurs when wine is excessively exposed to oxygen, causing a flattening of its character. The wine's aromas may resemble other oxidised wines like sherry. Oxidation can happen to old wines or young wines due to mishandling or errors in the winemaking process.
• Volatile Acidity (VA): This flaw is characterised by the odour of vinegar, with acetic acid being the primary contributor. While not harmful to health, it is considered a defect when present in high concentrations.
• Ethyl Acetate: A by-product of yeast fermentation, ethyl acetate can contribute to the perception of volatile acidity. At low levels, it adds desirable fruity notes, but in defective wines, it can dominate with an unpleasant nail polish remover-like aroma.
• Mousiness: This off-flavour is reminiscent of caged mice or crackers, rendering the wine undrinkable to sensitive individuals. It is typically caused by certain strains of lactic acid bacteria and is more likely to occur in wines with low levels of sulphur dioxide and acidity.
• Hydrogen Sulfide (H2S): Producing a "rotten egg gas" aroma, hydrogen sulfide is often a result of yeast stress during fermentation or the presence of elemental sulphur on grape skins.
• Unwanted Sulfhydryls (Thiols/Mercaptans): With aromas described as "cabbage", "garlic", "onion", or "rubber", these compounds are generally considered defects when present above the sensory threshold.
• Dimethyl Sulfide (DMS): Found in aged wines, DMS contributes to the "vegy" or "blackcurrant" character at low concentrations. However, higher levels result in an off-aroma described as "asparagus", "cooked corn", or "molasses".

It is important to note that the perception of these off-aromas can vary among individuals, and some contaminants, such as Brettanomyces, may be tolerated or even appreciated by some wine enthusiasts.

The impact of oxidation

Oxidation is an unavoidable part of the winemaking process. It occurs when the oxygen in the air comes into contact with the alcohol in the wine, causing the alcohol to convert into acetaldehyde, a flat and sour-tasting organic compound found in fruits, breads, coffee, and wine.

Oxidation can begin in the vineyard when a grape is ruptured and continues throughout the pressing and fermentation processes. It can also occur when wine is left open to the air for too long. The use of a faulty cork may also allow too much air to enter the bottle and affect the wine.

The word "oxidized" typically carries a negative connotation when used to describe wine. Oxidized wines tend to lose vibrancy in both color and flavor. White wines begin to brown, while reds lose their ruddy hue and turn orange or russet. If exposed to air for too long, the wine can turn to vinegar.

However, oxidation is sometimes used intentionally by winemakers to draw out certain flavors and create desired effects. The term "oxidative" often describes wines with nutty, savory, or umami characteristics. Oloroso sherry, for example, may yield hazelnut notes due to oxidation. Other wines may develop notes of raisins or brown apples.

While oxidation can be detrimental to a wine's chemical makeup, it can also be used as a tool to control vegetal aromas or impart nuttiness or yeasty characteristics.

To prevent unwanted oxidation, winemakers can reduce the wine's exposure to air during crushing and fermentation or add sulfur dioxide, which neutralizes the oxygen and prevents it from oxidizing the wine.

The role of swirling

Firstly, swirling the wine increases the wine's exposure to oxygen, which has several benefits. Oxygen helps to enhance the wine's aroma by making the aroma compounds more detectable as they attach themselves to the evaporating alcohol. It can also help to soften harsh tannins in bigger wines, making them smoother and silkier. Oxygen can also help to "blow off" any unwanted aromas, such as those caused by sulfites, which can give off an odour of burnt match or rotten eggs when a bottle is first opened.

Secondly, swirling the wine allows you to observe its appearance better. As the wine moves up the sides of the glass, you can more easily see its colour and the gradient it creates. This is especially important as the colour of a wine generally corresponds to its style. For example, a dark red wine is likely to be fuller-bodied and richer than a pale pinkish one.

Swirling also gives an indication of the wine's viscosity or thickness. A dense, tannin-rich wine will tend to spin more slowly and stick to the sides of the glass. When you stop swirling, the wine forms "legs" or "tears" that can indicate the wine's viscosity and higher alcohol levels. The more legs you see, the more alcoholic the wine is likely to be.

Additionally, swirling creates a more varied and complex tasting experience. Agitating the wine increases its surface contact with the air, creating little bubbles. The air is full of oxygen that dissolves quickly in the wine, reacting with the aromas and generally making them more pungent, fresher, and fruitier. This enhances the overall taste of the wine, making it a little bit better.

Finally, swirling is a great way to aerate your wine and release all those wonderful aromas. There are hundreds of compounds in wine, and the act of swirling enhances the volatility of these molecules, allowing them to evaporate more easily and waft upward. So, swirling is definitely not just for show—it serves a very important purpose in helping you to fully appreciate and enjoy your wine!

Frequently asked questions