The aroma that a wine carries is what makes it so remarkable to the taste. It is comprised of the primary tastes that the human tongue can experience, which include sweetness, bitterness and acidity. However, a wide range of different flavours can fall under this banner, with everything from the fruity through to the floral notes that you will experience while drinking a glass of wine all being a part of the overall aroma.
Furthermore, the aroma also refers to the smell of the wine before it is tasted, which is why you can commonly recognize notes while smelling that you will also notice when you are drinking the wine. Some mistake the aroma for the bouquet, but they are actually quite different. This is because the bouquet actually refers to the fermentation and aging of the wine, rather than the various aromas that can be experienced by smelling it.
Aroma vs Bouquet
While most laymen will quite happily refer to the wine’s aroma as its bouquet without giving it any extra thought, professionals will be quick to inform you that there is a definite distinction to be made between the two, with the trained nose being able to pick out both the aroma and bouquet, separating and appreciating them for what they bring to the experience.
To put in it is most simple terms, an aroma refers to the smells you will experience that are unique to the grape varieties that have been used to create the wine. For example, you will be quick to note an aroma of blackcurrant when drinking Cabernet Sauvignon, which is an aroma that is specific to that sort of grape. Generally speaking, the aroma will be most easily smelled when the wine is still very young, as it is the process of aging and the chemical reactions that happen during this time that give rise to the creation of the bouquet. In some areas, the aromas are broken down into primary, secondary and tertiary, allowing drinkers to enjoy different experiences as the wine ages.
The bouquet, as alluded to, comes much later and is essentially the smells that are created as the wine ferments and more chemical reactions occur. For example, smells of honey or similarly complex examples would more likely be a part of the wine’s bouquet, rather than its aroma, as they are not smells that would naturally occur with the grape and have instead come to light because of the careful composition of the wine allowing for them to be created over time. In many cases, it will be the bouquet that you will smell in addition to the aroma when you open a bottle of red wine and it takes a fairly skilled nose to be able to separate the two.
Thankfully, this is more the domain of sommeliers and other experts, rather than the casual wine drinker. For most, the terms aroma and bouquet can be interchanged fairly readily, though it is useful to know that there is an actual difference between the two that could be worth keeping in mind if you are trying to impress somebody with your Italian wine knowledge.
The Components of the Aroma
Now that we know a little bit more about the concept of the wine’s aroma and how it is different from the bouquet, let’s take a look at the various components that craft the smell in the first place. Within wine there will be a number of compounds, both volatile and stable, that combine to form the wine’s aroma. These compounds react with each other rapidly during the initial months of the fermentation process, which leads to the wine’s aroma changing rapidly over a short period of time. As such, the best way to determine the wine’s original aroma is to smell it when it is first starting to ferment, before keeping track of changes that result from these chemical reactions.
As the wine ages, these chemical reactions will start to slow down and the wine will approach the point of having the aroma and bouquet that it has when it is actually sold to the consumer. The most volatile aroma compounds are contained within the skin and the juice of the grapes used in making the wine, so as the skin is removed and the reactions with the juice start to slow down, you find that the wine itself becomes a little more settled and the aroma that you would be familiar with from that vintage becomes recognisable.
As a side-point, it is believed that grapes and the grapevines developed these aroma compounds in order to attract insects and other animals that would help when it came to pollination. As such, evolution has provided us with the perfect plant for creating wine and we should perhaps thank Mother Nature for this quirk of science that has allowed humans to create so many wonderful wines over the years.
Coming back to the compounds we were discussing earlier. The most volatile compounds that are responsible for the aroma you smell will often combine with the sugars in the wine to form an odourless glycosides, which serves to temper the smell of the wine somewhat in the process. This does not mean that the smell created by these compounds go away, as they will then undergo a process called hydrolysis, which is caused by the various acids and enzymes in the wine, that results in the aroma returning, often at a far more palatable level than in its purest form.
The Act Of Tasting
Now that we know a little bit of the science behind how and why the aromas we experience with wine are created, we move onto the subject of actually tasting the wine and experiencing those aromas.
The act of wine tasting, particularly the time you spend smelling the wine, is essentially the act of smelling the volatile compounds that were created through the process of hydrolysis. Your olfactory receptor cells will pick up this information and then transfer it to your brain by way of the olfactory bulb. This will allow you to smell the aromas presented by the wine and then be able to identify them while tasting.