Extract: The wines of Georgia by Lisa Granik MW

13 June 2022 by in Classic Wine Library, Extracts, Wine and spirits

Qvevri: the vessel of dreams
Qvevri are the clay vessels used for making wines according to the traditional Georgian winemaking method. (In western Georgia they are called churi.) They are found in the marani, more wine storage shed than cellar in some cases, but it can be a perfectly designed cellar. Whether attached to the house or nearby in the yard, the marani is akin to a sacred temple; indeed, it was often the site of surreptitious baptisms and other Christian rites during Georgia’s tumultuous history.

What are qvevri about, how are they made, and what makes them so special? For an object with a history that goes back thousands of years, the literature is remarkably sparse. For generations, qvevri-making and qvevri wine production were oral traditions handed down from father to son. It was only under Georgia’s ‘Golden Age’ in the eleventh to thirteenth centuries, and again under Soviet rule, that the empirical, technical and scientific aspects of the ‘Kakhetian Technique’ began to be broken down, analysed and taught. While they might have been in the library, these materials were made available primarily to wine science students and professional winemakers who already had learned the fundamentals of conventional winemaking. Home winemakers would not have sought out this information; their winemaking was based entirely on tradition.

At the same time, many nuances and personal experiences were never recorded. Even today, too few producers keep daily logs or detailed journals as to production procedures, treatments, rackings and so forth to inform future decisions and identify long-term trends. Only in recent years have researchers embarked on scientific study of qvevri and qvevri wines; much more needs to be learned. This part of the book explores the qvevri’s origins, method of production, use and maintenance, along with variations among Georgia’s provinces.

The exact origin of the qvevri/churi is unknown, but it is the centrepiece to all of Georgian winemaking historically. The earliest qvevri most similar in shape to those used in Georgia today were found in an Iron Age settlement near the town of Rustavi in eastern Georgia. This qvevri had a flat bottom, a stone lid, and was not buried.

It took some time for the qvevri to reach their current standard shape, as initially they were wide in the middle and tapered at the base and not buried. The shape of the ‘modern’ vessel continued to evolve from the third millennium BCE, as the bottom became increasingly pinched; it is theorized that this is when producers began to bury them in the earth, first to their ‘shoulders’ and, by the fourth century CE, up to the neck. The word ‘qvevri’ is thought to be derived from ‘kveuri’, meaning ‘something dug deep in the ground’. At some point before the Common Era, beeswax began to be applied to the interior. At a later date, a cement lining was added to protect the qvevri when they were delivered to their marani or as added protection in case of earthquakes or tremors.

Until very recently, what has been ‘known’ about qvevri was based on empirical evidence, although some preferred to invoke myths, legends and romantic stories. Two recent studies have endeavoured to develop a scientific understanding of qvevri production and use. The first was sponsored by Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ), evaluating the practices of a group of small producers; the second, a doctoral dissertation to examine the clay minerals and their effect on wine. This section will describe the traditional method of building qvevri and the implications of specific practices and choices.

Qvevri materials
The mineral content of the clay used for qvevri varies among the different quarries from which it is mined. This includes carbon and any organic matter, which must be burnt out; aluminium, silicon, quartz and feldspar are present in various proportions.

Production technology
In the past, qvevri were produced all over Georgia, but today they primarily are made in Kakheti (Vardisubani and Shilda), Imereti (Tkemlovana, Makatubani (Satsable), Shrosha) and Guria (Aketi and Atsana). They differ in shape depending on the origin. In Kakheti, they have a bigger middle bulge; in Imereti, they are narrower; in Guria, the exterior is ribbed.

The quarried clay is moistened and allowed to rest for one day to absorb the water, and only clean water from a running source, not spring or standing water, is used. The moistened clay is uneven, so it is put into a large grinder to grind, mix and homogenize the particles. Then the clay is shaped into logs.

Qvevris are ‘built up’ from the bottom nipple. There is no potter’s wheel; the tapered base is shaped and set on a wooden tripod. The clay logs (each about 10 centimetres in diameter) are layered, shaped and smoothed to build the sides. After each log is shaped and smoothed, it must dry for two days before the next is placed on top and smoothed into place. In inclement weather, it may be a three to four day wait for each new log. While each layer sets, the top is covered with paper to keep it moist while it waits for the next layer to be fixed. Several qvevri are built simultaneously. The qvevri maker has no measuring instruments, he simply eyeballs the growing vessel as he shapes it. ‘It’s a sensual, mystical, meditative experience,’ says Zaza Kbilashvili, a fourth-generation qvevri ‘master’ (his son will be the fifth). ‘You have a relationship with each one.’ It takes about two weeks to build up a thousand-litre qvevri. Once shaped, the qvevri sits for three to four weeks to set before it is fired. This is seasonal work, lasting only from March to November.

The kiln in which the qvevri is fired is a three-sided brick structure with openings about three-quarters up the back wall. The largest qvevri are inserted into the kiln in rows, with smaller ones fitted in between to fill the space. The fourth brick wall is then constructed; an opening at the bottom is left to insert the firewood. The fire burns around the clock and the temperature is judged by experience – Kbilashvili’s father knew it was time to take down the wall by the colour and nature of the emerging smoke. Kbilashvili peers in and judges by the change in qvevri colour – there is an evolution of four shades from brown to the final orange terracotta. The firing process lasts five or six days.

One of the challenges in qvevri production is that they were made according to tradition – without temperature gauges. The lower the temperature, the more porous the vessel and the greater likelihood of leakage. The Gamtkitsulashvili study found that vessels that are baked at 800 to 850°C impart a salty, wet clay flavour to the wine, negatively affecting wine quality. The rate at which the kiln heats up is significant; the GIZ study suggests first heating the kiln to 700°C, maintaining this temperature for at least one day to avoid cracks and fissures.

Over the next several days the temperature should increase to a minimum of 1,000 to 1,100°C and be maintained for at least six hours. If a qvevri cracks during the firing process, some masters may patch the crack. This may mask it, but it is not a permanent fix. In time (one to three years) the crack will reappear, the qvevri will leak, and the crack become a home for nesting bacteria and spoilage organisms, which negatively affects the wine for the unsuspecting winemaker. The qvevri is then useless for winemaking. Thus, producers are increasingly requiring contracts from qvevri masters guaranteeing replacement qvevri should problems arise after three years’ use.

Analysing the clay from three quarries, the GIZ study noted that the sintering process starts at around 820°C for the clay, and above 1,100°C or 1,150°C for the quartz and feldspar components, depending on the quarry. Thus, to obtain a homogeneously constructed vessel, the burning temperature must exceed 1,100°C (or 1,150°C for Tkemlovana qvevri). GIZ also recommends using natural gas to heat the oven as it can reach and maintain the high temperatures reliably. After cooling for three days, the kiln can be opened.

After the qvevri is removed from the kiln, beeswax is brushed on if the customer wishes; 1.5 to 2.0 kilos of wax is needed for a 1,000 to 1,500-litre qvevri. The main advantage of the beeswax is to smooth out the interior, making it easier for the skins, stems and juice to circulate during fermentation. Properly maintained qvevri need not be re-waxed. Problem qvevri may have their wax melted off and removed before the vessel is heat-treated to destroy harmful micro-organisms; the qvevri is then re-waxed. The wax penetrates the vessel walls, filling the pores, thereby minimizing the vessel’s porosity and preventing leaks. The wax-filled pores may cause a hermetic closure of the qvevri and prevent the ingress of oxygen into the wine (to the degree it happens at all). It also forges a barrier between the clay and wine, thereby inhibiting mineral leaching. The wax arguably also is more hygienic: the smoother walls are easier to clean, and the wax-filled pores are not available as nesting places for harmful bacteria.

Opponents of waxing contend that the beeswax has the potential for trapping and disguising bacteria within the qvevri pores; in time these bacteria may multiply and infect the wine. Research in this area continues.

In eastern Georgia, the qvevri are housed inside a stone structure. In the west, the qvevri (churi) traditionally were out in the open, surrounded by tall broadleaf trees for shade; though in Imereti, the churi were outside but often sheltered by a wooden structure such as a small shed or a roof held up by posts. Hygiene is more difficult when the qvevri are outside, as is temperature control. Hence, some western producers recently have moved their qvevri inside or are building structures enclosing them.

Qvevri are ‘planted’ into the ground in a marani or wine cellar. The wine cellar is dug out, the qvevri manoeuvred in, and the earth filled in around them. How they are planted is crucial as it is difficult to change or extract them afterwards. Some winemakers put approximately 1 metre of gravel as a top layer. This will prevent dirt from getting into the qvevri or, if cold water is poured around the outside of the qvevri walls, prevent overheating. Many, however, tile or cement the marani floor so that it can be washed. Bastien Warskotte has the necks of his qvevri several centimetres above the floor surface so that when he washes the floors of his marani, no dirty water or cleaning fluid can drip into them. Not all are so fastidious.

Modern qvevri range from 100 to 3,500 litres. As with any sort of fermentation vessel, smaller qvevri can be used for experimentation or when there is insufficient fruit available to fill a larger one. It is believed that 1,000 to 1,200 litres is the sweet spot for fermentation: smaller sizes may have difficulty maintaining the proper temperatures for fermentation; in the larger qvevri, there is a greater danger of the fermentation becoming too hot too quickly, thereby burning off some delicate aromatic qualities, perhaps shocking or killing the natural yeasts. Most producers will have qvevri in a range of sizes.

Peak fermentation for white wines is typically at 28°C in the larger qvevris; in 500-litre vessels, it often remains below 20°C. In classic Kakhetian white winemaking – with skins and some percentage of stems, depending on ripeness – the grapes and skins float to the surface of the qvevri due to the captured carbon dioxide; a few producers use a variation of a submerged cap but most punch down. Some may leave all of the solids in contact with the wine for as long as seven months. The fermentation typically lasts a week to twelve days.

While the malolactic conversion may occur simultaneously with the alcoholic fermentation, this is not encouraged for Kakhetian amber wines, which already have lower acidity levels. In Imereti, the lower pH levels and cooler temperatures naturally inhibit the malolactic fermentation. If the malolactic conversion is desired (as with red wines), some producers, before racking the wine off skins, may warm the receiving qvevri with a heating element.

Many small winemakers judge that the alcoholic fermentation is complete when the wine is no longer bubbling (there are both visible and audible cues); larger, professional producers perform laboratory analyses. Once fermentation has completed, the qvevris are then sealed.

Sealing the qvevri
In eastern Georgia, traditionally the qvevri were sealed by covering them with slate or other types of rock. Clay, mixed with a small amount of dry sulphur, is prepared to seal the lid. A sulphur wick would be lit just inside the neck, the lid affixed and weighted down; the sulphur smoke inside cools and forms a vacuum – the clay dries to form a hermetic seal. The stone is then covered with earth and dampened periodically to maintain the seal.

In western Georgia, the lid (called by a variety of names, including orgo, badimi, lagvinari) was wooden, made from chestnut, linden or oak trees. The lids would be soaked in water to remove bitter and coarse substances. A hole in the centre allowed carbon dioxide to escape during fermentation. The lids were placed directly on the qvevri, then covered with a thick covering of a yellow soil, packed down and moistened to create a thick clay. A tight complete seal is imperative to prevent oxygen ingress.

Qvevri cleaning
Just as producers differ as to their fermentation practices, so do they differ (sometimes vehemently!) as to their qvevri cleaning practices. There is no established cleaning protocol. Hygiene continues to be one of the greatest challenges in Georgia, not least because qvevri are notoriously hard to clean, given the porous nature of the clay construction and the qvevri’s immovable underground location. New producers may make an acceptable (or better) wine their first time, but are insufficiently vigilant about cleaning their qvevri, equipment and marani; later vintages show problems that accelerate over time. Part of the challenge is that cleaning is hard physical labour and also requires hypervigilant attention to detail.

Traditionally, first all solids would be removed, whether scooped out or vacuumed. Then a cleaner climbs into the qvevri and scrubs the walls to scrape off any particles that might be stuck. Various brushes, made from natural substances with antiseptic qualities, would facilitate the scraping. Hot water washing (without a person jumping into the qvevri) was also the practice in some areas and in big wineries during the twentieth century.

After scrubbing, the qvevri is rinsed several times with an alkaline solution. Producers vary as to whether they prefer the traditional ‘ash-wash’ (wood ashes mixed with water) or slaked lime (CaOH) solution. Caustic soda and sodium bicarbonate also may be used. Some might burn elemental sulphur to eliminate microbial activity, but producers differ as to whether this is ‘traditional’, even though it was available and used in Georgia before 1900. The next step is to neutralize the surface with acidified water, usually a citric acid solution.

It was long thought that empty qvevris were best stored clean and dry in a well-ventilated area to prevent mould. If this is not possible (especially as much of Georgia is humid), a soda ash or lime coating may be painted on the walls and neck of the vessel. Some producers are vehemently opposed to this practice, as the lime has the potential of raising the pH of wines that already have relatively lower acidities. Two modern alternatives include filling the qvevri with a sulphur/citric acid solution, checking it biweekly to ensure its condition and/or refresh it, or filling the qvevri with inert gas, then sealing it hermetically until it needs to be prepared for the new vintage.

Before the harvest, water is sprayed into the qvevri and the lime or ash coating is scraped out (this usually takes several hours for each one). The qvevri is then rinsed multiple times until the coating is removed and the rinsing water is fully clear, and then the next year’s grapes can be loaded in. And those grapes must be sorted, eliminating damaged or rotten grapes and any extraneous material, before being put into the qvevri.

Even trained winemakers admit that every year they may have fermentations that go awry: ‘You can think a qvevri is clean, but it’s not, and the next thing you know, the wine is ruined and you’ve lost [literally] a ton of fruit.’

Challenges to traditional winemaking in qvevri
Winemaking in qvevri is challenging and laborious – all the more so when one is committed to minimal intervention. The challenges often converge and cascade to produce wine that is muddled and not reflective of terroir. First, the fruit must be pristine, sorting out any damaged, rotten grapes and extraneous material; too many producers say they have no control over their fruit or say they do not have time to sort their fruit. Second, Georgia’s warm climate and the lack of temperature control in many wineries, plus the comparatively lower acidities, make the grapes and wines more prone to oxidation. While some oxidation may be a deliberate stylistic choice, oxidation nonetheless can abet microbial contamination and spoilage when winery conditions are more rudimentary. Third, the equipment necessary to facilitate cleaning and to ensure that the qvevri are perfectly clean is another capital expenditure that can be difficult for small producers without economies of scale. Nevertheless, it is crucial that the winemaker be hyper-vigilant about winery and equipment hygiene to ensure that the native yeasts drive the fermentations and spoilage bacteria remain at bay.

Extract from The wines of Georgia © Lisa Granik (Infinite Ideas, 2020)
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