All About Oak! Barrels and ageing

Now there’s a lot of information available about oak and barrels and ageing on the internet, but given we are the Spanish Wine Experience, and given that Spain just loves throwing wine into oak barrels, we thought it correct and timely to chime in with our two cents.

History

When we look at the Ancient Greeks and Romans we notice that those famous oak barrels weren’t present. In their place what we get are clay amphorae. This was the vessel of choice for both the wines and oils of the Empire. Fortunately we have a happy accident of the Romans deciding to push their reach to the north of Europe.

When they arrived in France they encountered the Gauls, beer drinkers through and through. And beer, that beautiful golden liquor of the north, is kept and transported…in barrels, often oak ones. Initially the Romans were enthralled by its strength compared to the more brittle clay amphorae and the fact that the tight grain was very waterproof. Then you had the roll-ability of them; much easier to move around. Also there was the geographical fact that the forests of continental Europe were teeming with oak trees.

The poetic moment was when, after hauling their wine around in barrels for however long, and at the end of a hard day’s empiring, they went for a glass of red wine and noticed the flavours and aromas had improved and the drink had become more palatable. In less than a couple of centuries, wooden barrels were the new modus operandi for winemaking.

Barrels, chips and staves.

Barrels

Barrels are king, but they are expensive (900-2000$ per item). 100,000 – 200,000 new barrels are sold each year just in North America so you can imagine how much money is flying about. It’s a big business and often one of the main expenditures for a winery.

Oak flavours are extracted better from trees with a tight grain – when the rings are close together – and this happens more in cooler climates: France (Tronçais, Vosges, Nevers) Hungary and Croatia, USA (Minnesota, Missouri, Wisconsin, Iowa). This then gives us ‘American Oak’, ‘French Oak’, etc.

A cooperage will cut, bind, toast (the level according to the intensity of the flavour the winemaker wants the wood to impart) and sell on barrels of different sizes. The ‘classic’ barrel for wine ageing is the 225L ‘Bordeaux’ or 228L ‘Burgundy’ size. Foudres, technically not ‘barrels’, can start at 2000L and reach 12,000L! But for ageing and flavour-adding you don’t want too large a barrel as the aromas will dissipate too much.

Chips and Staves (and beans and blocks)

A much cheaper, but less elegant and less well-regarded, method is to add something oaky to the fermenting wine while it’s in the stainless steel tank. Almost like adding a teabag to a pot of hot water or a spice bag for mulled wine. Though this method is cheaper and easier and can give a bit of aromatic lift to a cheap wine, it will never achieve the subtlety or elegance of leaving your wine in barrels.

Fermentation vs Ageing

Most wines are fermented – whether just the clear filtered juice of white wine or the juice + skins combo of red wines – in huge stainless steel tanks. This is essentially the process of making young wine: taking the must, adding temperature and yeast and letting the sugar turn to alcohol. Then, with your resulting booze, the winemaker may choose to fling it in a barrel and let magic happen. Reds are usually fermented in steel, as the temperature is easier to control and, to be frank, they’re also easier to clean.

Some wines are actually fermented in the barrel instead or as well as stainless steel. This will add oak aromas of course, but will also affect the structure of the wine, making them rounder, creamier and fuller. This is because the oak will allow tiny amounts of oxygen in and, particularly with whites, the wine will also be in contact with the lees (dead yeast cells and ‘bits’) that will add a yeasty breadiness. Not many wines are fermented in this way. It is very much a stylistic rather than necessary technique.

Now ageing is a different. Spain bloody loves ageing. At the turn of the 19th century an aphid-like pest called phylloxera ravaged European – particularly French – vineyards, decimating the land. It was the fault of Victorian botanists bringing American rootstocks – laden with the pest – over to Europe. With far fewer vines the Bordeaux winemakers went for help to La Rioja. The Riojans gave them wine and in return the Bordelaise left the concept of oak barrel ageing.

Your finished wine is left in a barrel and is monitored throughout its dormancy; making sure the wines are balanced as they age by sampling and blending.

The age and level of toasting of the barrel will affect your wine as it sleeps. The more heavy the toasting, the more spice and flavour imbued into the wine. The newer the barrel, the more intense the flavour. After four uses (4 years) the barrels stop imparting flavours and are called neutral. Then they are used for storage – which can still help mellow out wines and soften them.

American vs French vs Misc

There’s a lot of marketing and chat surrounding the different types of oak used in the wine industry. The reason for this is they affect the boozy juice in different ways. In short:

French Oak: generally more subtle in the imparting of flavours; often of spice, pepper and wood. Ideal with lighter, defter wines like Pinot Noir.

American Oak: imparts a lot of obvious flavour. Often those such as dill, vanilla and coconut (enter the famous ‘vanilla bomb Chardonnays’ of old).

Hungarian/Eastern European Oak: like a beefier version of French. Goes well with big wines like Malbec or Petit Verdot; attributing nutty rich and creamy aromas to the heftier tannic wines.

French oak is by far the most expensive though; so pure economics can often be an obvious consideration.

So what is the barrel actually doing?

Three main things are happening.

1. Adding the previously mentioned flavours and aromas. Phenols – flavour compounds – in the wood interact with the wine.
   1. 1. Vanillan – vanilla.
      2. Syringaldehyde – vanilla-ishness.
      3. Oak lactone – woody, coconut, herby notes.
      4. Furfural – dried fruits, roasted nuts, burned sugar/caramel.
      5. Guaiacol – burned flavours.
      6. (Iso)Eugenol – spices, smokiness, cloves.
      7. TOASTING – can vary the degree of toffee and mocha notes.
2. It provides a stable, waterproof environment for the wine to go through certain processes such as malolactic fermentation and lees contact.
3. The barrel allows a very slow ingress of oxygen.
   1. 1. Allows concentration of flavour and aroma compounds via the precipitation of the phenols.
      2. Small amount of oxygen also help to soften tannins.

And what are the rules in Spain?

Jóven – ‘young’ wine. No ageing in oak (but maybe a sneaky month or two to make it drinkable).

Roble – ‘oak’ wine. An unofficial wine usually denoting a ‘few’ months 3-6 in oak.

Crianza – minimum total ageing of 24 months – 6 of which must have been in oak. In La Rioja, Navarra and Ribera del Duero the minimum is 12 months in oak.

Reserva – minimum total ageing of 36 months – 12 of which must have been in oak.

Gran Reserva – minimum total ageing of 5 years – 18 months of which must have been in oak. In La Rioja, Navarra and Ribera del Duero the minimum is 24 months in oak.

So, as the owner of Bodegas Zifar in the Ribera del Duero once told me years ago, “barrels and oak ageing is not necessarily needed for a wine, but imagine the winemaker is a chef, then the barrels are the spices he can add to tweak his dish at the end and make it more complex and flavourful”. And I think that about sums up the beauty of it.