A bit of history
Clay vessels have been used to ferment and and age wine since the Neolithic Age and clay wine and vessels dating back some 6000 years, were recently found in the Republic of Georgia where they were tested and confirmed to be the world’s oldest. Almost every ancient culture, from the Egyptians tothe Assyrians to the Greeks and Romans, vinified in pottery vessels.
The term amphora is rather imprecise and is commonly used today to decsribe all terracotta vessels with two handles although to be correct, an amphora would be skinny, with a completely conical bottom and have hooked handles at the shoulders.It would be used for transporting wine on ships so would be small,stackable, and stored under the decks.
The true term for the large clay containers still used to this day in Georgia is qvevris. The Romans used similar flat-bottommed vessels that could sometimes hold as much as 3000 litres, known as « dolias ». Georgian qvevri are buried in the soil, while the Roman and Mediterranean peoples practice was free-standing pots above ground. Quite naturally due to the Latin influence, the Italian producers were the first reintroduce these ancient techniques followed by their neighbours in France, where it is growing in popularity especially for the vinification of micro batches of wines which lends itself to the use of smaller fermentation vessels.
Today's vintners
Some of today's wine makers look to reproduce the ancient techniques by burying the large containers although most have to settle for installing them in their vatting cellars. Most, but not all, of the wine makers employing these methods are organic and/or biodynamic and adhere to the natural wine mouvement's philosophy of zero or minimal intervention during the wine making process. Therefore grapes in perfect condition are required before vinifying in these 200 to 1000 litre vessels.
Why use terracotta vessels in wine-making ?
Terra-cotta pots offer unique interactive properties with wine that are different from those of stainless steel, wood barrels, or concrete. Notably, they pull out acidity as the clay reacts enzymatically with wine and raises its pH,allow oxygen exchange, and provide superior insulation, among other benefits. Clay allows oxygen into the wine twice as fast as wood. But the subtleties of oxygen transfer at each temperature constitute additional variables that winemakers can use to their advantage.
Furthermore, the temperature-regulating properties of clay are a major benefit. For example two tons of grapes will ferment for 30 to 35 days with peak temperatures around 20° to 22°C in clay while the same two tons of grapes in non-temperature-controlled wood or steel will finish fermenting in 10 or 11 days with temperatures reaching a maximum of around 30°C. The lower temperatures for clay-fermented wines create brighter and fresher wines.
Red and white wines are vinfied in thesame way and the contact between the juice and the skins enhances phenolic extraction which also enables increased stabilisation of the wines without the addition of S02, which also results in increased purity of the original juice. Maturation can vary from 6 to 12 months according to the estate. Once this period is over, the lees, pips and skins lie at the bottom of the of the vat leaving a clear wine due to natural filtration. Another benefit of clay is its natural clarification properties. While many winemakers stir in negatively charged diatomaceous earth to fine their wine, clay pots have this property built in. The wine can then be drawn off into smaller terracotta vessels or other neutral containers before being bottled around a month later. This process produces very pure red and white wines called « de goutte » since the remaining skins are never pressed.
Making the white (or orange!) wines
The more progressive Aussie winemakers have started to make orange wines primarily with Sauvignon Blanc, which works wonders in this style. You need to forget fresh,zesty flavours typically found in the varietal, these golden whites feel a lot weightier and broader in your palate. Orange wines have been described as robust and bold, with honeyed aromas, hazelnut,brazil nut, bruised apple, wood varnish, linseed oil, juniper,sourdough, and dried orange rind. Today, most white wines are made by pressing grapes, separating off the juice and discarding the skins, stems and pips to produce a wine that is pale in colour. If, instead, the juice is left to macerate and ferment on its skins, pips and possibly stems, you end up with a wine that looks orange – or a variety of hues ranging from yellow to orange, or even amber. So the whites are made using the whole berry rather than just the run-off juice, since the grape skins, pips and stems impart all sorts of antioxidants, oils, tannins (and of course pigment), that help protect the young, fermenting juice from oxidation. Pressed juice is much more difficult to work with given its susceptibility to oxygen, so it is perhaps unsurprising that when wine was first created, all wines – regardless of colour – would have been made in the same way. Because of all this, they taste very different from regular white wines and can have a sour taste and nuttiness from oxidation. Because of their boldness, orange wines pair excellently well with equally bold foods, including curry dishes, Moroccan cuisine, Ethiopian cuisine (like those spongelikepancakes called Injera), Korean dishes with fermented kimchi (bibimbap), and traditional Japanese cuisine, including fermented soybeans(Natto). Due to the high phenolic content (tannin and bitterness) and the nutty tartness they exhibit, orange wines pair with a wide variety of meats, ranging from beef to fish.
Making the red wines
This extremely natural way of vinifying produces wines with beautufully soft tannins since the wine is macerated, infused and the maceration is done slowly and gently,with a minimum of « violence ». The second is that it is also an ageing process given the overall duration of up to a year and then it is only sufficient to leave the wine in a second container for a month before bottling. The wines also satisfy the « anti-wood »lobby since the terracotta is neutral and therefore gives no flavour to the wines, conserving a purity of fruit which can be quite astonishing to those who are used to drinking wine that has seen even a little wood !
Conclusion
This quest for fruit and purity may just stand the test of time as it is part of a wider search for taste and authenticity, a direct transfer of the message of the terroir from the grape to the wine. Try some and see for yourselves !