It's no secret that wine ages and improves in the bottle. Wine barrels also age and improve, but it is less common knowledge how to use them for ageing or why they are beneficial. Wine can be aged in a barrel for years before it is ready to drink, and the final wine will be significantly different than if it was not aged at all. Wine casks come in many different types, all of which have their own intricacies of use and impact on the final quality of the wine.
Wine is stored in casks or barrels during this ageing process, each of which imparts unique flavours to the final product. Wine storage options are both plentiful and varied; there are many types of barrels that you can use for storing your wine, as well as various places where you can store them.
This article will explore each type of cask, what effect they have on the final wine, how long to store for optimum results, and how ageing improves both the final product and how ageing improves investment opportunities.
What Effect Do Barrels Have on the Flavours of Wine?
The type of barrel used to store wine has a surprising impact on the flavours of the wine as it ages. Wine is most commonly aged, matured or stored in oak barrels to enhance its flavour
Oak barrels are made from wood known as Quercus Alba. This type of oak is commonly grown in North America and many parts of Europe including France, Germany, Hungary, Lithuania and Slovakia.
There are a few primary ways that the wine interacts with the barrel:
Wine absorbs compounds from within the wood at different rates depending on its strength (alcohol content). These compounds include lignins, vanillin, wood tannins and sugars.
Wine extracts flavours from the pores of a porous material such as oak or cork. The space inside a barrel can vary between one third to three-quarters full which means there’s plenty of room for air to circulate.
This allows evaporation processes during maturation called “reduction” where alcohol begins to evaporate into the surrounding air and oxygen moves into the barrel.
As the alcohol evaporates, the wood extractives dissolve into the surrounding air and move into the barrel. This means that the wine gets more complex and rounder as it ages.
Wine is pushed up against the oak, which acts like a membrane (like cling film) trapping some of it in its structure but allowing other components to diffuse through over time.
The extraction rate of the flavours from the barrel depends on several factors including:
- Temperature – The warmer the storage environment, the faster the extraction rate because the increased heat causes more of both the wine and the compounds in the wood to become aerosolized, increasing their rate of absorption.
- Humidity – The more humid it is, the lower the alcohol concentration in equilibrium with air. This means that there are fewer molecules of ethanol to escape into the vapour phase and oxygen can diffuse through wood extractives into wine
- Barrel Size – Wine spends ageing less time in smaller barrels than larger ones. Wine in larger barrels takes longer to extract tannins and other phenolic compounds from the barrel, which increases extraction time. The smaller volume of wine in contact with wood also results in a slower transfer rate of oxygen through the char layer into the wines
- Oxygen – Oxygen is essential to maturing fine red wines because it allows for further polymerization and complexation reactions that contribute to structure and mouthfeel as well as colour. Barrels are often filled to 85-90% of their capacity in order to reduce the amount of oxygen that is introduced into them through headspace exposure to control this process.
- Diffusion – Wood contains cellulose, hemicellulose, lignin and other components which form a matrix through which oxygen diffuses. The rate at which this diffusion occurs depends on factors including wood species, degree of seasoning and the size of the wood vessel.
- Barrel Surface Area – Wine stored in smaller casks has less surface area through which it comes into contact with wood, so its potential for extraction is lower than if the wine was stored in a large cask
- The Volume of Wine – More wine in a barrel means more surface area and the potential for greater extraction.
- Higher Wine Alcohol Concentration – Wine stored in larger barrels has a higher alcohol concentration than wine stored with lower volume, which is why it takes longer to extract compounds from smaller casks
- Barrel Age – Wine aged in older wood contains fewer phenolic compounds. Consequently, it ages faster. Wine aged in younger wood contains more phenolic compounds. Consequently, it ages slower
- Wine Age – Wine ageing slows down as the number of extractives decrease, and stops once all extractives have been extracted from barrel staves Wine stored for longer has a higher concentration of flavour compounds than wine that is relatively young.
What Are the Different Types of Barrels?
The two most common kinds of oak wine barrels are bourbon and sherry barrels. Oak casks have a greater impact on wines due to their particularly porous structure which allows more oxygen transfer during fermentation than other types of casks do.
Oak has a huge influence on wine due to an enzyme called laccase which it contains. This breaks down phenols in red wines that can be harsh tasting and transform them into softer, rounder flavours.
A wine that has been exposed to this extra oxygen becomes deeper coloured, fuller-bodied and less acidic.
The wine aged in sherry barrels develops dried fruit flavours like raisins and figs.
Bourbon barrels impart strong vanilla notes as well as some spiciness although they can be very mild depending on what kind of bourbon they were used to hold.
Concrete barrels are most commonly used to age white wine because, while they are porous and allow oxygen in to aid in the maturation process, they also don’t add in any wood tannins.
This keeps the fruit flavours forward and keeps white wines crisp and refreshing.
Stainless Steel Barrels
As with concrete barrels, stainless steel barrels are used to store and age white wines because they will not add any flavour or scent to the wine and do not allow oxygen in, which results in a crisper, sharper wine with strong fruit flavours.
While oak barrels have been used for hundreds of years, stainless steel and concrete tanks are quickly gaining popularity because they offer more flexibility when it comes to using different grape varieties that may react differently with wood flavours.
Clay barrels are one of the oldest ways to age wine.
Clay barrels will not impart any flavour or scent to the wine being aged in them and have a porous material inside which allows oxygen to pass through very slowly over time. This slow oxidation process enhances certain aromatics in wine while developing complexity.
One of the benefits of ageing wine in clay is that it “softens” tannins over time, which can have a very positive effect on fragile red wines by reducing astringency and harshness.
Optimum storage environment
The optimum storage environment for storing wine in barrels is a cool, dark cellar. Wine barrels are porous and allow a small amount of evaporated wine to pass through the wood over time. This is known as the ‘Angels’ Share’.
This means that wine stored in wooden barrels requires regular maintenance by adding more wine or topping up with other wines.
The best way to keep this kind of loss is to store the barrel on its side rather than upright, where this evaporation is less likely to occur, In a room with ambient temperatures of 18-22°C and around 50% humidity will ensure your wine remains in optimum condition for as long as possible.
How long should you store wine for?
\Wine can be aged in a barrel from six months up to two years depending on the type of wine you’re storing, your location and the storage conditions.
For example, if you live in a hot climate then it’s less likely that wine will age well. The warmer temperature speeds up the ageing process; making it more difficult for wines to mature at their own pace.
If you’re storing reds (for example cabernet sauvignon), these can be aged for around 30-months before they start deteriorating due to oxidation processes within the wine itself.
White wines are usually aged for a much shorter amount of time, around 6-8 months.
These short barrel ageing periods are because again the wine in the barrel for too long can result in it absorbing too many tannins, in a process called ‘over oaking’. This can lead to the wine because unpleasantly bitter with a distinct woody aftertaste.
Once the wine has finished ageing in the barrel, it can be transferred to bottles to continue to mature without contouring to absorb flavours from the material the barrels is made out of.
Most white wines should be consumed within about three years of being bottled.
However, there are exceptions to this rule, such as full-bodied chardonnays which can be kept for up to three-five years or Roussanne, which is at its best between three to seven years. Fine white wines from Burgundy, such as French Chardonnays, are best enjoyed at 10-15 years of age.
Bottles of red wines are often aged for a much longer period compared with white wines because more time spent maturing brings out their more intense flavours.
For example, cabernet sauvignon based wines from Bordeaux can be matured in oak barrels anywhere from 18 months up to 12 years depending on how they have been produced by winemakers.
Tannins within the grape skins will dissolve over an extended period allowing full flavour development throughout its life cycle resulting in a really smooth tasting wine.
After ageing in the barrel, the wine is transferred to bottles where it continues to develop until it is ready to drink.
This process often takes a minimum of a further six months so the wine can ‘rest’ and allow any sediment created by the ageing process to settle at the bottom of each bottle.
Barolo and Bordeaux are two of the world’s greatest red wines. They’re great examples of age-worthy beverages that will benefit from a longer maturation process. Barolo matures and reaches its peak after around ten years.
With time, the tannins in these wines tend to lessen rounding out their flavours and giving them more depth.
Red Bordeaux blends can age for a couple of decades as long as they are stored in the right conditions.
Not all red wines require a long maturation period. Pinot noir has excellent acidity, a fragrant bouquet and a sour cherry flavour that will eventually fade. So it’s better to not wait too long before drinking good pinot noir.
How Many Bottles Do You Get from a Wine Barrel?
The answer to this is obviously going to depend on how big the barrel is. Wine barrels are most often measured in gallons.
A standard bottle of wine is 750ml, which is about 1/5 of a gallon. This means that, for each gallon of wine you have in the barrel, you can turn that into five bottles.
So, if you’re ageing your wine in a large 60-gallon barrel, you’ll end up with approximately 300 bottles of wine.
A more standard-sized 30-gallon barrel holds around 150 bottles worth of wine.
Ageing Actively Improves the Wine…
Ageing wines in different types of barrels has been shown to have many benefits including increased complexity, flavour intensity as well as decreased levels of harsh tannins.
Ageing actively improves the wine by allowing it to become smoother as well as improving its aroma qualities such as complexity and intensity which are why most connoisseurs will not open an expensive bottle until several hours after it was bottled so that all the components of the wine can fully develop.
Most fine winemakers will age wines for up to two years in the barrel before bottling it to further improve their quality.
Ageing wine can change a wine that is little better than grape juice into something more complex and enjoyable while also allowing some of the harsh flavours found in young wine to mellow out.
Ageing wines in a barrel is expensive and time-consuming but it’s worth every penny if you like your reds to be smooth, complex and mature and your whites to be crisp and fruit-forward.
…and Improves Its Value as an Investment Opportunity
Fine wine is an excellent investment opportunity because it holds its value and often increases in price over the years. Wine connoisseurs make up a large and growing community of investors who purchase wines because they enjoy them or simply to add to their collection and sell at a higher price when it’s ready for consumption.
Investing in fine wines has become markedly more popular over the last few years because of the resistance of the market to economic downturns.
The market for fine wine is global, which makes it appealing to investors of all types and from various countries around the world who are looking for attractive returns on their investments in an increasingly unstable economy with low-interest rates.
The fine wine market is also expanding, with increasing interest being shown in fine wine by the rapidly growing Asian markets.
Although there are many other opportunities for investors in fine wines, the final benefit is that it’s an investment with a good chance of increasing in value over time.
Ageing wine can significantly add to its value because older wines have complex flavours and aromas which evolve over years stored inside barrels. The reason why old wines gain more flavour complexity comes down to the tannins present in wine.
Tannins are large molecules that give red wines their colour and texture, but they also act as a preservative for wine during storage because of how astringent they are.
Tannin levels change over time due to oxidation, so older wines naturally have more tannin than younger ones. This is why ageing wine can help create complex flavours by slowly breaking down these larger molecules inside barrels.
The art of ageing fine wine involves storing it in oak barrels before bottling them after around 18 months or longer until there’s enough flavour complexity built up that makes the final product worth much more money than an un-aged one would be sold at on release date.
It should also be remembered that wine is a consumable. Even as the wine you have in your collection is maturing, the wine currently on the market is being drunk or purchased into other collections, increasing its rarity and market value.
Savvy wine investors are able to purchase a good wine and turn it into something spectacular and highly valuable with the right combination of barrel ageing and maturation in the bottle.