What Happens to Wine as it Ages?

If you are a lover of fine wine, you are probably familiar with the term "aged" to describe a bottle of vintage wine. However, are you aware of the fundamentals processes an aging wine goes through? Do you know what happens to your wine as you leave it sitting in a wine cellar for years? Well, for starters, ALL wine that is left to age will change. Wine is a living, breathing liquid that will taste slightly different on any day you choose to open it. Among the alterations of mature wine, you may find differences in its taste, texture, aroma, colour, and even overall quality.

Despite the expectations of many wine lovers, it is important to understand that not every aged wine will become more flavourful, higher quality, or simply better over time. Some wines become less desirable when they are left to age because they are don't contain enough of the compounds required to create a good mature wine. So, let's examine the science behind mature wine and how to know if you should or shouldn't age your bottle and pop it in your freestanding wine fridge.

Colour changes as wine matures

How a wine changes in colour tends to be determined by the type of grape varietals that make up the wine, the amount of time the wine spends in contact with the skins and its original hues. Over time, as oxygen interacts with the molecules in your wine as it inevitably will as the wine matures, it will cause colour-changing chemical reactions. Another reason for aged wine to change colour is its tannin concentration. Let's take rose wines, for example. As rose wines age, the colours darken, forming a more brick red over its original orange-pink shade. This is because the tannins soak deeper into the wine and darken its colour. However, if we take a white wine and age it, you will notice the colours begin to enrich. A change from a lighter golden colour to a richer yellow-gold colour is more often the result of over-oxidation than heavy tannin concentration. Red wines lose depth of colour as the compounds and tannins drop out of the wine and form sediment.

Flavour changes as wine matures

There will be changes in flavour and mouthfeel as a wine matures with bold reds becoming lighter in weight and more ethereal, prime fruit aromas giving way to tertiary aromas and oak flavours reducing in power over time. White wines in contrast can become more flavourful and develop heady flavours of white chocolate and hazelnut.

Aroma changes in mature wines

Red wine, white wine, sparkling wine, sweet wine, fortified wine, and others all undergo the oxidation of aromatic chemical compounds over time. Oxidation occurs when air leaks through the wood's pores when barrel aging and through the cork when bottle aging wine.

During the aging process of white wine, oxidation occurs at different rates depending on storage, temperature and closure. The primary aromas from a long aging period include wax, honey, nuts, hazelnuts, pine resin, detergent, and Greek clover (an aromatic seed, also referred to as fenugreek).

On the other hand, red wines undergo oxidation for several years or even decades due to their slower oxidation process than white wines. As a result, there is a high concentration of polyphenols in red wines, which have powerful antioxidant properties. During a long wine aging period, significant aromas are derived depending on the wine type, a Bordeaux may show aromas of earth to truffles, gunflint to cedar as it enters twenty plus years.

Optimal Temperature for Maturing Wine

Experts agree that when you are maturing a bottle of wine long-term, keeping your storage at 12 degrees celcius is optimal. Higher temperatures can prematurely age and spoil the wine, while lower temperatures can slow down the aging process.

You can store your bottles in a cellar that remains around 12-13 degrees Celsius (55.4 F) all year long. However, it is imperative that you maintain the proper temperature to avoid ruining your precious bottles. One of the easiest ways to age your wine under the right conditions is to invest in a quality wine fridge. A Coolersomm wine cabinet can keep your wine at the proper temperature and help regulate humidity and UV light.

What wine cooler features are needed for long term wine maturation

  • Reliable Temperature - Many wine cabinets in the 1980s and 1990s came without a changeable temperature setting. It was 12 degrees or nothing for many from Eurocave and Climadiff because that is the one temperature you need for long term wine maturation. Today tefmperatures can be chosen but whatever temperature you decide on you need that temperature to hold steady; especially when the ambient temperature drops.
  • Winter System - If you're keeping your wine cabinet in a place where the temperatures never drop below 12 degree then you don't need a winter system. If your storage space is a garage or cellar, you will need to ensure the wine cooler can also be a wine 'heater'.
  • Humidity Management - All wine coolers have humidity management but some allow the user to choose their ideal level of humidity.
  • Solid Door or heavily protected UV door - Maturing wines really prefer complete darkness, even over heavily UV protected blackened glass. The solid door options from Artevino and Climadiff are perfect for wine maturation.
  • Carbon Filter - Lastly, you dont want bad odours permeating the cork and creating off compounds in your wine, you'll need a charcoal filter in the wine cabinet and most all wine maturation cabinets have them.

How do You Know What Bottles to Age?

Many wines are intended for immediate enjoyment, so you should not age most bottles you buy. It's very unlikely that even that £30 Barolo from Asda or £15 Saint Emilion are going to improve with age. The result will be a decrease in quality and a poor flavour profile if you attempt to mature a wine that is not intended for aging. These undesired flavours are often caused by spoilage, meaning the wine is no longer safe to consume. Conversely, there are some fairly low priced wines that can indeed mature for decades happily, some Rioja and Rieslings come to mind.

Suppose you do invest in a nice bottle of wine, say a £50 or £100 bottle and decide to leave it in your wine cellar to age. In that case, you can use this over-simplified list to the standard aging potential in wine categories:

Red Wines:

  • Merlot: 7–17 years
  • Cabernet Sauvignon: 10–20 years
  • Zinfandel: 5-10 years
  • Malbec: 10 years
  • Syrah: 5–15 years
  • Pinot Noir: 10 years

White Wines:

  • Chardonnay: 10 years
  • White Rioja: 10–15 years
  • Muscadet: 3-5 years
  • Garganega: 6-8 years
  • Viognier: 4 years
  • Sauvignon Blanc: 4 years
  • Pinot Gris: 3 years

It's probably worth visiting the producers website, or using the Coolersomm product table to know how long a wine can be matured for as there will be Chardonnay's capable of maturing for 30 years and some that should be drunk on the way home from the supermarket!

How Can You Tell if an Aged Wine is Still Drinkable?

We've all drunk an out of condition wine haven't we? Sometimes we knew by the cork, the smell, the colour and certainly by the time it reached our lips, we knew this was a tipple destined for the kitchen sink:

Here is what you should be looking for when opening that mystery bottle:

Checking the Cork: The first thing you want to do is examine the cork. You are looking for holes and deterioration, indicating that the wine may be over-oxidated. A weakened cork can also allow bacteria and other germs to enter your wine bottle. Although the alcohol content will kill off most bacterium types, acetic acid bacteria can survive and spoil your collection of fine wine. Has the wine crept a long way up the length of the cork? If so, beware!

Taking a Whiff: Looking for a quick way to determine if your wine has spoiled? Open the bottle and take a whiff. A wine that smells sour or unpleasant clearly indicates that it has spoiled and should not be consumed. A bottle of bad wine can have a sulfuric scent, smell musty, or hint at rotten fruit.

Evaluating the Colour: You can tell your wine has spoiled by the colour of it. If your once-white wine is now murky and appears yellowish-brown, it has probably aged past its expiration date. As for red wine, a spoiled bottle would appear as an intense, deep purple (almost black) or even brown!

Bottling it All Up

By researching how to mature your wine and doing your due diligence, you will ensure that your wine has reached its optimal quality when you pop the cork. There is nothing more disappointing than opening a bottle of wine that has matured, just to discover it is not what you were expecting, or dreadfully, it has spoiled and you waited too long. Aging wine takes years of patience but when you get the date right, can offer great vinous joy.

Our tips for maturing wines are 1) Learn about the wine making process of this wine and pay some attention to drinking windows 2) Buy a case of a wine and open your first bottle a little ahead of the middle of the drinking window, this will give you a point from which to evaluate its maturity and when to open the next bottle in the series and 3) Buy a wine cabinet and don't let your wines prematurely oxidise or cook!

Sarah newton

Author - Sarah Newton

Sarah Newton has worked in the wine industry for two decades holding senior positions at some of the UK wine industry's leading brands. The MD of Coolersomm, Sarah is WSET certified and our lead wine buyer too.