What role does ageing play in winemaking?
One of the most important secrets of winemaking is preserving the taste of wine. Wine is not made to be left in the open air, as it soon becomes unpleasant.
The ancient Phoenicians (2500BC - 0BC) were the first to export wine across the Mediterranean Sea in ceramic containers called amphoras. Traders preserved wines by pouring a layer of olive over a ceramic amphora to prevent oxygen getting in. The airtight method later allowed Romans to trade wines across their empire and establish the Old World wine regions, so the skill of ageing wine is really tied up with the history of wine itself.
As in Roman times, all wine undergoes a primary fermentation. Winemakers allow freshly-pressed grape must to ferment as yeast fungus converts most of the sugars into alcohol and carbon dioxide (yeast is often added). But primary fermentation starts to slow down after a week or so, and without a barrier of carbon dioxide wine can begin to oxidise. Alcohol and oxygen will start turning into acetic acid, which gives flavour to vinegar. Wine that's gone bad turns brown and you'll be able to taste and smell the pungent vinegar tang.
In some parts of the world, like in Spain, rancid wine is sometimes provoked by leaving jars of wine out in the sun and then used in making pastries. Generally it's not pleasant to drink though.
Until the 17th century, French winemakers were still stuffing oil-soaked rags into the necks of glass bottles to stop oxidation and keep their wines tasting and looking great. Legend says that Benedictine monk Dom Pérignon stuck a piece of bark from a cork oak into the bottle neck and – voila! – the wine industry had a wonderful solution allowing them to keep wines airtight for 100 years of more.
Bark from the cork tree opened up new possibilities for winemakers as it helped keep wine bottles airtight, even up to 200 years.
Does ageing continue in the wine bottle?
Even when sealed off from the air, nature does not stop trying to make wine ferment. For centuries, winemakers noticed activity in barrels and bottles as soon as spring brought some warmth following winter and the primary fermentation. In 1837, German enologist Freiherr von Babo called this the 'secondary fermentation'. It turned wine cloudy and made winemakers rack wine into new barrels and add sulfur dioxide to stabilise it.
In 1866, Louis Pasteur discovered that bacteria caused wine spoilage, and later on enologists discovered it was bacteria fermenting malic acid and sugars into lactic acid without the presence of oxygen. Before getting into too much science, malic acid is common in fruits and gives unripe apples and rhubarb their sourness – reminds you of any racy young wines? Lactic acid bacteria plays a role in decomposing plants in the wild, and does this by breaking up sharper malic acids into softer lactic acids with a taste profile described as 'milky' or 'buttery'. You'll know the taste of lactic acid from yoghurt, sauerkraut and cheese.
During the 1950s enologists like Emile Peynaud began encouraging winemakers to control and even induce malolactic fermentation. This is because malolactic fermentation consumes many of the leftover nutrients that other microbes could feed on and spoil the wine. Controlled malolactic fermentation lets winemakers future-proof their wine while also adding a silky-smooth taste, most famously in reds like Cabernet Sauvignon and Shiraz.
Malolactic fermentation – say that after three glasses!
Today, many winemakers take advantage of the secondary fermentation, keeping wine in airtight oak barrels or stainless steel vats and adding lactic acid bacteria on purpose. This allows winemakers to created full-bodied wines of high complexity and rich, toasty, nutty and buttery flavours that shouldn't undergo any more rapid fermentation processes. Instead, a gradual malolactic fermentation can continue in the bottle to turn harsh and bitter tannins into silkier tones, reduce sourness from the malic acid into more palatable flavours and tone down the astringency of young wines. If you're building a wine cellar, you'll be wanting to pick a wine that keeps on giving.
Seriously well-made wines will continue to dazzle drinkers through the decades due to expert winemakers getting the chemistry and the art in perfect balance for your palate.
Many winemakers will control the secondary fermentation of wine in oak barrels, often ageing wines up to years at a time.
Does ageing make wine taste better?
Whether ageing makes wine better is a matter of taste. White wines and rosé wines might lose their appeal after just a year of production because the sharper acids have gone flat during malolactic fermentation. White wines and rosés are not made like red wines, which tend to undergo primary fermentation along with their skins and have more body to stand up to the processes of ageing. But that said, many of you will be drinking white wines and rosés for their youngness and freshness of acidic flavours.
Coates' Law of Maturity is a wine tasting principle that a wine will remain at its peak drinking quality for a duration of time equal to the time of maturation required to reach peak quality. It's estimated around 90% of global wines are made quickly for consumption within a year of production, so if you're thinking of building a wine cellar you'll definitely need to be looking for wines that have spent time developing in oak or otherwise built to last.
Wines that are prepared for ageing tend to be more expensive, because the winemaking process requires more skill, more time and more resources, like oak barrels. French oak barrels can cost twice as much as American oak barrels, and are prized for adding a creamy, silky quality to wines – particularly with Chardonnays. Both French and American oak barrels are likely more expensive that stainless steel vats or oak staves or chips, which allow for fermentation but don't add as much complexity.
When it comes to drinking and enjoying aged wine vs young wine, that's all down to you. If you love smooth, rich Cabernet Sauvignons with silky tannins, or creamy and buttery Chardonnays, then ageing will make wine much better for you as the tannins resolve with time. If you like the youth and acidity of a fresh rosé, then there's nothing wrong with choosing a young wine. Sometimes just knowing how to taste the differences can make the whole process more enjoyable, as you have a deeper conversation with each wine. And the most important is knowing what you prefer and your tastes will change with time.
In essence, you could think that a wine built for ageing is a wine the winemaker wanted you to taste that way. To soften the sharp acids and tannins, a winemaker might want to give their wines time to develop a more delicate mouthfeel. Or a winemaker might want to give a sharp Sauvignon Blanc some toasty, nutty and spicy aromas to bring the wine to life. Sometimes winemakers will put a percentage of a white wine through malolactic fermentation, adding texture and body to the wine without losing remaining floral, citrusy notes.
Whether wines taste better with ageing is a matter of preference, but aged wines are typically the most expensive with the most expensive bottle sold to date is a 1945 Romanée-Conti at US$558,000.
Explore your wine tasting preferences
If you're new to wine or wish to deepen your experience it can be great to purchase a crate of six and take notes as you drink it over the years. At first, you might find it too fruity and fresh, and after a year or two you might find a sublime balance of flavours you'd never known before. It might seem a long experiment, but time in the pursuit of your enjoyment is never time wasted.
At the UMAMU Estate, we release our wines often years after harvest as we dedicate our efforts to drawing out the best flavours from the Margaret River wine region. We developed our 2018 Rosé for longevity with four months ageing in French oak barrels on lees before bottling. The result is a floral rosé sparked with spice and softened through fermentation to last in your wine cellar for years, and a rarity among modern rosé wines.
Here are three more UMAMU Estate wines from the Margaret River that we released after spending ample time in barrels and in the bottle and in the museum cellar: