This is how we roll

Oaked, or unoaked, that is always the question, layered with a myriad of answers to help winemakers reach their intended flavour and structural destination.

A maturation cellar stacked with oak barrels is a quintessential image that awaits you when visiting a wine estate. Just imagine the sweet-musty smell of an old cellar, the coolness and silence quenching your thirst for some serenity. And then, the only rhythmic sound echoing throughout the cellar being that of someone rolling a barrel.

Oak barrels are but one of the vessels used in modern winemaking today. While similarly shaped clay amphorae and concrete eggs bring their own style quintessence, oak barrels complete the romantic image of winemaking throughout the centuries.

Consumer preferences for specific aromas have sent the wine industry foraging for the best French, American, Hungarian, and Slovenian oak coupled with sophisticated technology doing it justice. But, as the price for a 225L American oak barrel starts at US$ 470, Euro 770 for a French oak barrel and Euro 700 for an Eastern European oak barrel, can make a long-term decision pretty daunting.

As part of the Cape Winemakers Guild Protégé Programme, each Protégé can make their own wine and is sponsored a barrel of choice from the Cape Cooperage Group. As a subsidiary of the Independent Stave Company, a family-owned business founded in 1912, they are also community-focused, making the Protégé Programme a good fit for the Cape Cooperage Group in South Africa since 2010.

Given complete freedom to follow a style that showcases their talent, this wine represents everything they have learned under their mentors in this highly successful skill development programme. The members of the Guild play a pivotal role in mentoring the Protégés to strive for perfection, and excellence, which ultimately includes stylistic decisions and the use of essential resources like oak barrels.

Andre Kotze, managing director of the Cape Cooperage Group, is thrilled to be associated with a programme that helps build future wine generations:

"Partnerships are the foundation of our business to craft world class oak barrels and cooperage products. Our wine and oak experts work with winemakers to create comprehensive oak programs that achieve specific sensory targets for their unique cellar.

Absolute control from raw material to finished products and with the ongoing inventions and improvement of technology set us apart from competitors. We also provide tasting samples and run ongoing trials to share the possible influence of each with the wine industry."

A recent tasting demonstration on how oak plays a pivotal, yet supporting role to express a particular wine style, grape varietal, origin while honouring its ageing potential and the price point in mind was a big revelation for Protégés attending the event.

"Depending on the barrels' toasting level, they impart certain flavours and add tannins to give a wine structure. Oak barrels also ensure micro-oxygenation that assists with maturation," Andre explains.

He shared that the barrels the Protégés prefer to indicate the style of wine people like to drink, "extra fine grain French oak barrels with seasoning and specific toasting showcasing fruit with the foundation to age."

Graduating Protégés showcasing their own wines on the 2021 CWG Protégé Programme Auction that opens on 17 September, used Tonnellerie Quintessence 225lt French oak Hydro-Dynamique and Tonnellerie Quintessence 500lt French oak Hydro-Dynamique respectively for their Chardonnays. They opted for Tonnellerie Quintessence 225lt French oak Traditionnelle Longue and Tonnellerie Quintessence 225lt French oak Hydro Dynamique for reds. 

The tasting at their premises in Zandwyk Park, outside Paarl, included a control wine from which three to five examples had different oak treatments. Coupled with an in-depth presentation of their oak sources in North America and France, it included aspects from microclimates suited to ancient oak species to the scrutinous selection process of buying logs on auction. All these certified forests have sustainability management programmes with a life cycle of more than 100 years.

"We use oak from two French species: Quercus Robur and Quercus Petraea. For wine barrels, we focus on using these species in fine grain and extra fine grain. The appropriate grain selection, seasoning and toasting allow us to control the different compounds as Cis et trans-Whiskylactones, lactones and the different phenolic characters.  The American oak comes from the Quercus Alba - a thin grained oak tree found in North America producing oak with a light phenolic character but with more intense lactones.

All these intrinsic qualities are considered when they recommend a specific oak regime for a particular style of wine.

Andre and the team introduced the different brands: World Cooperage, Heinrich Cooperage, Tonnellerie Quintessence and Tonnellerie Tremeaux, by illustrating the effect these products can have on a particular wine.

The tasting revealed exciting conclusions about oak chemistry and how toasting releases and caramelises simple sugars: a light toasting adding creamy-fudge flavours, medium toast bestowing more toasty and sweet caramel flavours on the wine.

Whereas the traditional toasting method included the barrel positioned over an open fire, state of the art technology has also enabled coopers to use sophisticated heat sensors.

"There are 108 toasting profiles. These heat sensors monitor time and temperature, ensuring strict adherence to the defined toasting curve, irradicating any inconsistencies."

The complex nature of oak stretches far beyond what you can smell and taste, and one needs to comprehend the chemical composition of the oak used in winemaking. Oak comprises cellulose, hemicellulose, lignin, and oak tannins. With minimal direct flavour effects from cellulose, it functions as a transporter of extractives. The hemicellulose contains wood sugars that add body to the wine. Often coupled with toasty characters, it can also affect the colour of a wine, albeit this is where lignin comes in. Apart from adding a deeper shade to wine, it adds complexity and sweeter vanilla notes. It also helps to remove off-notes. Lastly, oak tannins also help remove any vegetal or off-flavours but play a more significant part in the wine's astringency, texture, and colour of the wine.

As consumer palates have become more sophisticated, longing for more unadulterated fruit purity in their wines with less overt oak, so have the manufacturers of barrels turned up the heat as far as refinement goes. However, the heat is toned down as far as delicate nuances in the cooper-craft go, bearing exceptional results. With evidence of the first watertight, wooden barrel used for wine around 350 BC, to a mobile app enabling you to create a hybrid barrel, one can rest assured there is a barrel to complement any wine.

Did you know:

Oak derived characteristics include:

  • tannic: structure, length, volume, velvety texture
  • resin: freshness, menthol, eucalyptus
  • Herbaceous: weedy, tobacco, mown hay
  • Woody: cedar, sawdust, pencil shavings
  • Lactone: coconut, celery, dill

Toast derived flavours include:

  • Spices like cloves, cinnamon, and nutmeg
  • Sweet aromas like caramel, honey, and butterscotch
  • Vanilla, including waffle cone and extract scents
  • Toasty nuances like toasted bread, coffee, mocha and light roasted nuts
  • Smoky aromas like bacon, campfire and burnt sugar
  • A chemical note like ash, burnt match and tar

Microbiologically derived aromas:

  • Yeasty: butter, popcorn, bread dough
  • Earthy: mushroom, leather, shoebox