The image of a wine barrel is inextricably linked to our modern idea of winemaking, but the history of the oak barrel begins over two millennia ago – where the Romans first met the Gauls. As the Roman Empire expanded, transporting wine in relatively fragile clay amphora became problematic, but from the Gauls they learned how to use oak barrels for their wines. Oak was abundant in the forests of Europe, softer and easier to bend into the barrel shape than other types of wood used at the time, and the tight grain made it waterproof.
It was not long after the oak barrel’s popularity as a storage medium took hold, that winemakers realized the wines became imbued with certain positive characteristics, improving the taste. This established the practice of aging wine in oak – to this day, an essential practice in winemaking. Three types of oak are most commonly used in modern winemaking: French oak (Quercus robur), American oak (Quercus alba) and – to a lesser degree – Hungarian oak (also Quercus robur, but with slightly different characteristics than French oak).
The effect of oak on a wine is two-fold. Firstly, the oxidation effect that is created from the slow movement of air through the porous oak staves, serves to react with the wine and soften the tannins. Then, the oak imparts secondary flavour components to the wine, like vanilla (from the chemical compound vanillin), cloves (from a compound called eugenol), and caramel or butterscotch (from furfural).
At Oldenburg Vineyards, we use a combination of 225-, 300- and 500-litre barrels. Since Nic joined the team in 2018, we’ve shifted to using more 225 L barrels (from 300 L), as they are the traditional sized barrel used in Bordeaux, and they are a bit easier to move around. We also use 228 L barrels on our Chardonnay, which is the standard size for Burgundy. The 500 L barrels are used with our Syrah, as the bigger barrels are used more for Rhône varietals. The larger the barrel, the lower the ratio of wine in contact with the oak. This decreases the oaking effect, compared to the smaller 225 L barrel. All our oak barrels are tight-grained French oak.
Check back with us next month for The Role of Oak – Part 2, where we will discuss coopering, toasting of the oak as well as alternative vessels, such as Austrian wood foudres and concrete eggs.