Maturation and aging of wine
This is a duo that causes as much confusion as the aroma and the bouquet. We will present a few explanations to differentiate the terms and to show how they actually influence the taste of the liquid in the glass.
Obsolete does not mean expired
Many believe that "outdated" is synonymous with "expired" - that is, an outdated wine is only good to throw away. Others, on the other hand, read somewhere or saw a clever documentary that said that the longer a wine stays in the bottle, the more valuable it is over the years. For example, those bottles, recovered from the bottom of the oceans, from the galleons sunk by pirates.
In terms of "maturation", the opinions are a bit more uncertain: matured means a more serious wine, right?
Reactions that change the composition of the wine
The maturation and aging of the wine generically refer to a set of reactions that improve, over time, the taste and aroma of the wine. "Maturation" refers to the changes that take place in the wine after alcoholic fermentation and before bottling.
At this stage a series of natural or chemical processes take place, induced by the winemaker, during which the wine periodically comes into contact with the air. This triggers oxidative reactions that bring changes in the composition of the liquid. "Aging" refers to changes that occur after the liquid has been bottled. Because, even trapped inside the glass container, the wine continues to evolve.
Not every wine can be aged
These are wines that enrich their taste and aromatic palette following the maturation and aging processes. However, there are also wines that are evolving rapidly: for them, prolonged maturation and aging does not increase their quality.
Fresh, fruity, light white or rosé wines, red wines intended to be consumed young - in general, wines that go on the market one year after they were produced or even in the year in which they were produced - are in a phase of decline in a relatively short time since when they were produced.
On the other hand, wines obtained from certain varieties (Cabernet Sauvignon, Merlot, Fetească Neagră, Pinot Noir - for red wines, Sauvignon blanc, Chardonnay, Italian Riesling, Riesling de Rin, Pinot Gris, Fetească Albă, Tămâioasă Românească - for white wines) can develop a rich aromatic palette during ripening and acquire an interesting bouquet after bottling.
Mith vs reality
Contrary to many people's beliefs, good wine cannot be kept indefinitely. Of course, a quality product, stored under controlled conditions, can evolve nicely over the years, even decades, to the point where the decline begins.
Usually, most white wines should be consumed within 2-3 years of production, and most red wines should be bottled within 5 years. The key factors that indicate the aging potential of a wine are the alcohol concentration, acidity, fruitiness and tannin content (for red wines).
Good to know: red wines can be kept a longer time inside the glass than white wines - especially reds that have been previously stored in wooden barrels. (The wine barrel - barrique – has a capacity of 225-litres).
What reactions are taking place in wine
The reactions that take place in the wine, during maturation and aging, are either subtle, so difficult to detect in the final product, or, on the contrary, very observable. There are changes in colour, aroma, consistency, taste. Let's take them one at a time:
è Colour. The most noticeable changes in the maturation and aging stages are related to colour. Whether it's white or red wines, their colour turns brown over time. After fermentation, the red wines change from bright purple to ruby, then brick.
White wines turn dark after fermentation: from greenish yellow or straw yellow, they become golden, amber, and then take on darker tones.
è Taste and consistency. When a wine is matured and aged correctly, it acquires a special consistency, it becomes softer, more velvety, more full-bodied.
The changes are due, among other things, to the polymerization of phenolic compounds in wine (ie tannins), especially in red wines. As they polymerize, the molecules increase in size and precipitate. This leads to a decrease in the astringency of the wine and its bitterness.
è Aroma. In all types of wines, red or white, the fruity notes and aromas of fermentation are lost, and new flavours are formed. The aromas of fresh fruit disappear starting with the ripening stage, the wine acquiring instead the so-called ripening bouquet.
Then, after bottling, the liquid is enriched with the aging or glass bouquet. For white wines, the esterification and hydrolysis reactions, as well as the degradation of some terpene compounds lead to the loss of varietal aromas (given by the variety from which the wine was made) and fermentation.
In parallel, new compounds are formed that contribute to flavour. When maturing wines, the decrease in the concentration of compounds that give specific flavour (terpenes) is offset by the formation of less volatile oxides. They change the aromatic profile of the wines, from the floral one to one with exotic notes, of eucalyptus or pine.
Advantages of barrel (barrique) maturation
Maturation usually takes 6 to 24 months, but may take less - or longer. During all this time, the wines are stored in stainless steel tanks or in wooden barrels and can undergo various operations - malolactic fermentation, clarification, processing and so on.
Thus, it comes into contact with air and absorbs small amounts of oxygen, which does not harm the aromatic profile. As for the aging in the barrel, it is reserved for quality wines. Liqueurs extract various compounds from wood that add aromatic complexity.
The wines are enriched with lignin and the so-called ellagic tannins, which have an effect on their consistency, taste, colour and smell. If the wood of which the barrel is made has different degrees of burning, this adds to the liquid specific flavours of caramel and toast.
In short, the barrel favours the oxidation processes, softens the tannins and gives the liqueurs typical aromatic notes - vanilla, tobacco, chocolate, coffee, butter.