Why does wine go into oak barrels?
Why does wine get aged in oak barrels?
The Historical Reason for Oak Aging:
Before the advent of glass bottles in the 1600s, wine found its home in wooden barrels—a testament to the historical roots of oak aging.
While modern technology offers lots of storage and transport options, the allure of oak persists, enriching red & white wines (and whisky) with its distinctive taste.
How do Oak Barrels Affect the Wine?
Oak has three main effects:
- Adds flavour, aromas of vanilla, clove, smoke and coconut
- Allows for slow and controlled aging of wine, though the wine evaporating and being replaced with oxygen
- Provides an environment for Malolactic Fermentation to occur.
Malolactic fermentationn is also known as Malo and makes wine taste creamier.
What flavours does oak add?
We're not allowed to add falvour additives, such as grapefruit, melons or nuts; unlike beer. Oak is the accepted way to affect the taste of wine, the oak flavours combine with the wine's flavours to creat a variety of new and different tastes.
Typical oak flavours are:
- almonds, dried fruit
- burn overtones
- woody and coconut
- spices, cloves and smoke aromas
- vanilla
What about new vs old oak?
Oak flavours reduce each time a barrel is used.
It's expediential, so in the second year you get half the oak flavour, and in the third year of use a quarter of the original amount of oak flavour.
How long a wine spends in barrels depends on the winemaker's vision and plan for that specific wine.
For example Upper Reach's Reserve Shiraz is a big, robust fruit driven wine; so it can handle half brand new oak and half one year old oak for 12-18 months.
But that would overpower a more delicate wine....our Grenache only spends about 9 months in older oak barrels, to give it that lovely but very much a background hum of oak.
Barrel Sizes: Barriques, Hogsheads?
The larger the oak barrel the less oak flavour and oxygen (aging) goes into the wine.
Barriques are traditionally 225 litres, however at Upper Reach we prefer to use Hogsheads which are 300 litres; we prefer this proportion of oak to wine.
The largest format is a Foudres, technically an oak barrel but at approx 20,000 litres it acts more like a stainless steel tank.
French vs American Oak:
French oak is more dense, the rings are closer together, its been suggested this could lead to in lighter oak flavour and lower oxygenation of the wine.
French oak is used for lighter wines, like Chardonnay, wheras American oak is used for bolder wine, such as Cabernet that can balance American oak's robust flavours and more oxygen ingress.
Barrels help to speed up the wine's aging:
Evaporation in oak barrels, often referred to as the 'angel's share,' plays a significant role in the maturation process of wine.
As wine ages in oak barrels, typically 200-400 mls evaporates per barrel each fortnight. This evaporation process concentrates the remaining liquid, enhancing the wine's flavors and aromas. To ensure the wine stays fresh, we top each barrel up every fortnight...see winemaking isn't all about sitting around and drinking wine!
Moreover, the porosity of oak allows for micro-oxygenation, where tiny amounts of oxygen permeate the barrel, subtly affecting the wine. This controlled oxygenation helps in softening tannins, leading to a more rounded palate and developing the wine's depth and complexity.
If we didn't top the barrels up, there would be too much air to wine, excessive oxidation which would ruin the wine, turning it into (very expensive) vinegar.
How much does an Oak Barrel cost?
An oak tree typically only makes two barrels, trees take a number of decades to grow and coopering the wood into barrels is very skilled.
At the moment the price of a new wine barrel is around $2550.
This adds on about $8.50 in raw materials to the cost of a single bottle-
Overall the oak flavours along with evaporation and oxygenation within oak barrels are vital processes that contribute to the unique characteristics and high quality of wines aged in barrels.