Wine dictionary: learn about the power of aftertaste and how to spot an oxidised wine

In this article we’re starting off with the term ‘oxidation’. Do you know what it means? Put simply, oxidation just means the process in which oxygen comes into contact with a wine and gets dissolved in it. This sets of a string of reactions with other substances in the wine, such as polyphenols, iron and copper, among others.

In general, oxidation is not exactly desirable, but sometimes it forms part of another process in winemaking and can even be beneficial

There are two types of oxidation:

• Enzymatic or biological oxidation: this is particularly quick and affects both the wort and the grapes when they arrive at the winery. This takes place just before wine fermentation.
• Non-enzymatic or chemical oxidation: this is a slower oxidation process that happens as the wine is ageing after it has fermented. This transformation can give wine a certain stability and even improve some of its characteristics.

Wine oxidation is measured in millivolts (mV). When this is at a rate of 200-300 mV, this is deemed to be a normal level of oxidation. However, this largely depends on the type of wine, how it’s handled in the winery and how it’s stored. When you go beyond this range, the oxidation detracts from the flavour and the quality of the drink.

So, how can we easily tell if a wine is not oxidised at home? Mainly based on changes in the colour and flavour of the wine. White wine oxidises at faster rather than red wine. However, both get darker, shifting towards a brown colour.

To avoid oxidation, you should finish off the bottle in the recommended time after uncorking it and make sure that you keep it in the right conditions at home.

In line with the previous term, we’re now moving onto a interesting concept: “pricked wine”. What does it mean? If someone tells you a wine is pricked, it means that the flavour is off, which means it’s not suitable for drinking.

This issue is caused specifically by oxidation, the presence of oxygen and acetic acid bacteria. The latter are bacteria that metabolise ethanol and also cause other processes that gives wine a slight unpleasant acidity or even turn it completely sour.

How can we tell if a wine is pricked? To avoid drinking a pricked wine, there are some basic key tips to know how to spot one. There are many ways:

1. Knowing the vintage of the wine: if a wine has been stored for too long, too much oxygen might have gotten into the wine. You should be particularly aware of this with young wines or those that haven’t been aged for long, since they should be consumed within a shorter time frame. As such, the best thing to do is to take a look at the label to work it out.
2. Analysing the bottle: this is slightly more complicated; if the cork or the capsule are not in place, some air may have gotten into the bottle.
3. Looking at the wine: some pricked wines have a skin floating on top and some of them are cloudy.
4. Smelling the wine: this is easy to do, since the wine will have a strong vinegary smell.
5. Tasting the wine: don’t worry, it’s no poisonous. Just unpleasant. If the wine is pricked, it will be vinegary with a rough mouthfeel.

Let’s keep moving our way through the wine dictionary! The stalk (also known as the stem) is the structure that holds a bunch of grapes together. In other words, it's like their skeleton. Its main role is to hold up each of the grape, but it can be used for much more.

It can play a key role in winemaking. Any idea how? Because, whether or not it is included in the winemaking process can affect many aspects of the final product, such as the pH level, the tannins, fermentation, colour, aroma, etc. So, what’s best? Traditionally, it was very common to include it in the wine. However, now it depends on the criteria and choice of each winery.

This is the sensation that wine leaves in the mouth, throat and nose after tasting it. One thing we just love about wine is its lasting power. In fact, when it comes to tasting wine, we should just look out for the aromas we get before and the flavour when we drink or spit it. We should also be looking out for the notes that it leaves behind once we’ve tasted it.

That’s why, when we talk about ‘lingering in the nose’ or ‘lingering on the palate’.. We’re talking about notes of the aftertaste which can tell us about the quality of the wine. If these aspects last for quite some time, then we have a wine that’s ‘long in the mouth/nose/throat’. If it doesn't linger, then we have a ‘short wine’ (of a lower calibre).

Don't worry if you can’t make out some of these characteristics. We need to train our senses slowly so that they get sharper over time.

Let’s take a look at the last term in our Wine Dictionary. This is a word that professionals often use, such as sommeliers on wine tastings. But what do we mean when we say a wine is round?

Pamela Vandyke, a famous British wine journalist, gave a very good definition and the reasoning behind it. In fact, her definition is the benchmark today.

She said: “Many people find it helpful to think of wines as having a shape. Some immature wines often seem to be angular, other seem straight up and down in slightly unripe vintages. A round wine has its skeleton (the alcohol) adequately and pleasantly covered with flesh (the fruit) and is enhanced by a good skin (the fragrance). Excess rotundity shows a lack of proportion, but many young wines possess a type of puppy fat which they shed later.”

In more colloquial terms, if we call a wine ‘round’, we generally mean that it is well-balanced. In other words, a wine that is balances out all of its elements, such as acidity, sweetness, tannins, alcohol level, fragrances, body, etc. As such, harmony reigns among them.