Dit artikel werd origineel op 14 augustus 2012 gepost op http://en.vinoge.com/history/qvevri-liming-and-washing.
Oorspronkelijke titel: Qvevri liming and washing
From: Making Wine in Qvevri: a Unique Georgian Tradition, Tb. 2011. © elkana
By Giorgi Barisashvili
Making wine in qvevris and maintaining these special vessels have been given much attention by Georgian specialists and viticulteurs. Both in the past and the present, qvevri washing and sanitation have played such an important role in Georgia that there was a special occupation known as “qvevri washer”.
Washing a qvevri well is an important precondition for producing quality wine. However, in addition to washing, other preparations of a qvevri before it is buried in the ground are also important. Coating the outside surface of a qvevri with lime and the inside walls with melted wax are both necessary.
Concerning the first process, liming qvevris, the process should be carefully studied. Cement mortar was once used for coating qvevris instead of lime. This is a mistake, because although cement is known for its strength, lime lasts longer especially when the qvevri is buried in damp soil. While lime on a qvevri can be preserved for centuries, a cement coating is limited to ten or twenty years; after this it begins to deteriorate. Contrary to lime, cement is also prone to molding under humid conditions, which adversely affects wine quality. Lime is not only resistant to mold, it is also noted for its antiseptic action. In fact qvevris can be buried without any coating at all but liming a qvevri strengthens it and improves the winemaking process.
A. Bokhochadze wrote concerning qvevri liming in “Viticulture and Oenology in Old Georgia Based on Archeological Materials, Tbilisi 1963: All the qvevris found in the excavation of maranis, some dating as far back as the Middle Ages, bear signs of liming. To lime qvevris, a lime grout(1kg lime— 2kg sand), rubble stone and sandstone fragments, sometimes fragments of qvevri and other earthenware crockery are used. As it appears, qvevri liming is carried out locally, in the ground. In such cases, a pit for a qvevri is dug in the marani, on the bottom of which a flat stone is placed to accommodate the qvevri bottom or heel; the qvevri would be stone-faced around and coated with lime mortar. The qvevri liming is carried out bit by bit. When one stone-facing is completed, the second stone-facing would begin, and so on. The mortar thickness can be 10 to 25 cm. The mortar was applied to ensure that the qvevri cannot be removed. As the weight of a limed qvevri can be several tons, its displacement is practically impossible and in most cases will cause it to break. Therefore, the qvevris limed in one place usually remain there forever, even when the marani itself is moved and arranged in another place”.
The qvevri washing process is primordial since wine quality greatly depends on cleanliness. Since the quality of wine must be preserved by liming and waxing, a mistake made during washing may lead to irreparable spoilage. Washing qvevris, as mentioned already, has always been critically important. An interesting extract from the newspaper Meurne (Farmer) published in 1888 describes the technique: We know that a qvevri usually has stuck dry pomace, mold and other dirty substances on its walls. Before one sets out to washing the qvevri, I advise first to get rid of this dirt. For this purpose, newly burnt lime should be poured into a trough or a big barrel and poured over with water. The next day, when the lime precipitates, clear water should be sprayed on the qvevri insides; the lime water will eat away the dirt. After that it should be poured out of the qvevri and replaced with boiling water, then the qvevri should be covered with a lid; the steam will completely soften the dried pomace and lees, after which the qvevri can be easily washed”.
This little passage showshow much importance the authorattached to cleanliness. Characteristic phrases, such as “qvevri smell”, “vessel’s touch” and “smacky wine” set us thinking that our ancestors could clearly recognize the smell of wine fermented in a poorly washed qvevri and, more importantly, could distinguish this smell from other diseases or defects of the wine. When the qvevri is properly washed (which seems to be more problematic today than it was earlier), the wine fermented in it will have no “smack” or “off” taste and smell, especially when the wine itself is sound.
Too oftenimproper washing leadsto irreparable consequences. If, for example, the previous wine productionwas defectiveor diseaseresulted frompoor hygiene, it can frequently infect future yields in the qvevri as well. Thus a mistake made once will harm the winegrower over and over again.
As seen from the example above, lime water is one of the best qvevri-washing agents. To prepare it, a slaked lime solution is used. Although there are no precise proportions for preparing qvevri-washing lime water, current practices allow us to estimate the mixture of lime and water in the proportions of 10-15 l water to 3-5 kg lime. After the lime has been burnt and well dissolved in the water (after 2-3 hours at least), the lime water should be separated from the precipitated unsolved lime particles, thenthe qvevri-washing lime water will be ready for use. Naturally, washing large-size qvevris will require more lime water.
Lime water should be spread evenly on every part of the qvevri then the qvevri should be thoroughly brushed by a “qvevri brush” made from the roots of St.-John’s wort or by a hand brush, rinsed first with cold, then with hot water, at about 60ºC, two or three times.The qvevri should be washed until thoroughly clean which will also depend on its condition. When this is done, it should be rinsed finally with warm or cold water. It will be considered asproperly washedand usablewhen the water left becomesabsolutely clear and devoid of any taste or smell.
In practice ashor a sodium water solution (formerlyknown as “ash-wash”), can also be used for washing qvevris instead of lime. Both lime and ash are natural and therefore safe cleansers and do not damage the vellel walls, unlike soda (especially caustic soda) which damages qvevri walls like other chemical agents. Qvevris can also be washed with cold thenhot water, without any cleansers, although washing with ash-wash or lime water is more effective.
In general, qvevri washing is very laborious especially when the qvevri washer had to enter a large-size qvevri. He had to position himself carefully inside the vessel to carry out the work effectively. In these cases one or two dry bunches of vine stalks were placed at the bottom so the qvevri washer could stand and work. Of course qvevris have to be washed with only fresh potable water. On interior surfaces of very big qvevris (for example, 5000 to 7000 liter capacity qvevri)the qvevri-maker added steps from top to bottom, also made of clay, so that the washer could go down and up inside the qvevri more easily. The steps also served as supports for a board on which the washer could stand or sit to work.
Wine lees and tartrates tend to eat deeply into the qvevri’s porous walls, and removing them takes effort. The main problem for a qvevri washer is not the obvious dirt on qvevri walls but the grime found deep in the pores of the walls. This is the main danger to wine in terms of quality deterioration.Such dirt should only be removed by cold or hot water. In ancient times however, qvevri washers effectively applied lime water and ash-wash for the purpose.
In addition to qvevri washing with lime we can look at the application of ash which, as already noted, is effective poses no problems for the storage vessel or quality deterioration when applied properly. Anywine residues in qvevri such as tartrates, colorants, lees, etc. are acidic, whereas ash is a weak alkali anddissolves such residue.
To prepare anash-wash,sifted wood ash ispoured into water, mixedwelland boiled. Proportions are 1-1.5 kgof pure sifted ash to 3-5 liters of cold or boiling water. The ash sediment should be separated from the liquid wash mixture which is then ready for use. Formerly ash-wash was used for washing hands, face and head, as well as for plates and dishes and otherhousehold utensils.
The qvevri is rinsed before the ash-wash is applied. Following the lime/ash treatment it should be rinsed first with cold and then hot water, and then finally re-rinsed with cold or warmish water.Ash is applied both in the form of ash-wash or as dry ash if the newly washed qvevri has remained empty for some time.In such cases the sifted pure ash is spread over the whole inner surface of the newly washed qvevri, while the walls are still wet. The qvevri walls will dry and the ash will stick to them, effectively preventing the development of harmful microorganisms in the wall pores. Although such qvevri washing requires comparatively more effort it is justified to better protect the qvevri walls.
Also to disinfect qvevri walls, sulfur can be burnt inside the vessel, in the following proportions: 3 g sulfur for 100 liters of volume. Applying a larger dose, up to three times bigger, is not harmful. Sulfur can be burnt in qvevris after ash has been poured into them. It can be used both in powder form and as prefabricated wicks. In both cases, melting sulfur dripping into the vessel should be avoided to prevent giving the wine an odor and taste of rotten eggs.
Fumigation with sulfur is possible just before the qvevri is filled with wine or even earlier when it is empty, even once every two months, for example. If the sulfur burning in the qvevri takes place immediately before filling it with wine, pulp–or must—the process should still be preceded with washing. Pouring wine into an unwashed qvevri is inadmissible! The sulfur must be burned in a freshly washed wine vessel while its insides are wet. At this time, the smoke of the burnt sulfur reacts with the moisture remaining on the qvevri walls to produce sulfuric acid. This goes into the pores of the inner walls to disinfect and cleanse the dirt.
Sulfur burning is also carried out in dry qvevris that were previously washed, though the cleansing effects are lesser than if it was just washed. After washing, if the qvevri remains empty for some time, sulfur should only be burnt in it once it is dry or else the smoke of sulfur reacting with water drops will dry and form a white-yellowish crystal coating on the inside walls. This can give a bitter taste to the wine and make it “rough” as a result.