Wine Aroma: Does Price Affect Your Nose's Judgment?

Wine aroma, or nose, is the smell of the wine in the glass. The human nose can differentiate between thousands of unique scents, and it is our olfactory abilities that allow us to distinguish the variety of flavours in a single sip. The tongue, on the other hand, is limited to sensing salty, sweet, bitter, and sour. The aroma of a wine is influenced by the grape variety used, the winemaking process, and the wine's storage conditions. Primary aromas are derived from the fruit or grape itself and may present as fruity or floral scents. Secondary aromas are derived from the winemaking process, with the most common influence being oak. Tertiary aromas develop as wine ages, and may include oxidative characteristics like coffee, caramel, toffee, and cocoa, or earthy notes like mushrooms or wet forest floor. While expensive wines may have a certain concentration that less expensive wines lack, it can be challenging to determine the price of a wine through tasting alone.

Primary aromas are linked to the grape variety and its soil and climate

The primary aromas of wine are linked to the grape variety and its soil and climate. These aromas are specific to the grape variety and are most noticeable in varietal wines. For example, lychees with Gewürztraminer or black currant with Cabernet Sauvignon. These aromas are commonly associated with young wines.

The grape variety and its soil and climate influence the volatile compounds that give wine its aroma. The Vitis vine is thought to have developed these compounds as an evolutionary tool to aid in procreation by attracting insects to assist with pollination and birds and other animals to eat the berries and disperse the seeds. The diverse spectrum of aromas associated with individual grape varieties is a reflection of the vine's adaptation to ecological conditions and competition among other plants.

The grape aroma is synthesized in grape berries by a variety of enzymes, including terpene synthases, O-methyl transferases, carotenoid cleavage dioxygenases, and cytochromes P450. The genetic variation in these aroma biosynthesis genes causes differences in aroma between grapevine varieties. For example, an allelic variant of 1-deoxy-D-xylulose-5-phosphate synthase, a terpenoid biosynthetic gene, causes the accumulation of terpenoids in Muscat and Gewurztraminer grapes, giving these wines a distinct floral aroma.

The temperature and light during grape ripening also influence the primary aromas of wine. Higher temperatures during ripening limit the herbaceous vegetal notes of wines, which are linked to methoxypyrazines, specifically IBMP (2-methoxy-3-isobutylpyrazine). Exposure of the grapes to light and the removal of basal leaves that contain IBMP during the nouaison-grape closure stages of the vine also amplify this effect. On the other hand, higher temperatures and light exposure increase the concentrations of carotenoid derivatives, especially C13-norisoprenoid derivatives, which are associated with fruity notes in wines.

In summary, the primary aromas of wine are linked to the grape variety and its soil and climate through the influence of various enzymes, genetic variation, and temperature and light conditions during ripening, which all contribute to the development of volatile compounds that give wine its unique aroma.

Secondary aromas are derived from the winemaking process

For example, if a Burgundy wine has been aged in oak casks, it may express secondary aromas of vanilla and clove. Malolactic fermentation adds notes of butter, cream, and/or cheese, while lees ageing can result in toasted brioche and bread dough aromas commonly associated with Champagne.

Other secondary aromas can include biscuit and yeasty notes from lees stirring and autolysis (the effect when yeast dies off), or the buttery popcorn aroma from the fermentation of many Chardonnays. Oak ageing can also impart desirable characteristics, such as vanilla, clove, smoke, coconut, or coffee.

Tertiary aromas develop as wine ages, especially in wooden barrels

Tertiary aromas are the result of the maturation and ageing of a wine. They are also known as evolution aromas because, during the ageing process, the wine's aromas are modified. This evolution is caused by the supply of oxygen, which causes chemical reactions that transform the balance of these aromas.

Tertiary aromas are developed during the barrel and bottle ageing processes. Storing wine in barrels allows oxygen to slowly enter the wine, which is what brings about nutty aromas, such as walnut, toasted almond, or hazelnut. Contact with the barrel also imparts its own aromas to the wine, which can vary depending on the type of oak. For example, American oak barrels tend to give intense notes of vanilla and coconut, while French oak barrels provide spicier scents like cinnamon, cloves, molasses, or cocoa.

After barrel ageing, wines are often left to rest in the bottle, usually in a dark, cool, and underground place, with no exposure to light. This is the final stage of wine ageing, and the wine continues to develop and acquire new aromas due to the mix and chemical reactions that occur in the alcohol, oxygen, water, and acids in the wine. In this stage, wines can develop notes of leather or truffles.

The sediments of dead yeasts that end up on the bottom of the barrel after fermentation are called the lees. Ageing on lees is the process of allowing the finished wine to rest on the lees to give it a new flavour profile. When cells in the lees decompose, they release aromatic compounds that interact with the chemical makeup of the wine, resulting in aromas of breadcrumbs, walnuts, and yeast. This type of ageing is more common in white wines and rosés.

Wine aroma kits can help train your nose to identify the different fragrances

Wine aroma kits are a great way to train your nose to identify the different fragrances found in wine. These kits typically contain a collection of bottled aromas or fragrances found in wine, bottled in concentrated forms. By smelling these aromas and identifying them, you can train your nose to pick up on the subtle and obvious aromas in wine.

The Sommelier Wine Aroma Kit by Aromaster is a trusted reference for professionals and wine enthusiasts for almost 20 years. It is the world's most comprehensive collection of wine aromas, combining 88 aromas found in sparkling, white, red, and sweet wines produced around the world. With this kit, you can develop your wine-tasting skills and identify grape varieties, winemaking techniques, maturation, and even faults.

Another popular option is the Le Nez du Vin aroma kits, which are used across the wine industry. These kits range from £30 to £400 and are designed to standardise aromas, making it easier for you to identify fragrances consistently.

If you're looking for a more affordable option, you can create your own DIY aroma kit at home using dried spices. Black pepper flakes, vanilla extract, cedar chips, and other spices can be stored in small vials or mason jars to create your own wine aroma kit. While these may not last as long or be as accurate as commercial kits, they can still provide a fun and educational experience.

By using wine aroma kits, you can train your nose to identify the different fragrances found in wine, enhancing your wine-tasting experience and helping you make more informed choices when purchasing wine.

Wine aromas are perceived by the olfactory cilia in the nasal cavity

Wine aromas are indeed perceived by the olfactory cilia in the nasal cavity. Olfaction, or the sense of smell, is critical to perceiving the vast array of wine aromas. The human nose can differentiate between thousands of unique scents, and it is this olfactory ability that allows us to discern the variety of flavours in a single sip of wine.

The olfactory cilia are located at the top of the nostrils, in a small area no larger than a standard postage stamp. These cilia are essential as they contain the entry point to the olfactory system. The stimuli must be airborne to reach the cilia, and once they do, they need to find the right receptor to inform us of the aromas present. The more intense the odour, the more stimuli there are to activate the receptors and gain our attention.

The act of tasting wine involves smelling these vaporized aroma compounds. The olfactory receptor cells, each sensitive to a different aroma, pick up these compounds and transfer the information to the brain via the olfactory bulb. The tongue, on the other hand, is limited to sensing sourness, bitterness, saltiness, sweetness, and savouriness.

The process of olfaction can occur in two ways: the orthonasal pathway, which is direct through the nostrils, and the retro-nasal pathway, which is indirect and occurs when the wine is already in the mouth. The retro-nasal pathway involves molecules reaching the olfactory bulb from the back of the mouth cavity.

To fully appreciate a wine's aroma, it is recommended to spend a good 10 seconds swirling the glass to allow the alcohol to volatilize and release the wine's innate scents.

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