No less important than thorough cleaning and disinfecting, is the subsequent treatment of the qvevri’s interior walls. Although the inside walls of a qvevri can remain without any treatment at all apart from washing, and only a few make the effort to make wine in qvevris, they should carry out all the processes traditionally. Beeswax and only beeswax (not paraffin, chemical colors or other agents) should be used to coat the inside walls of a qvevri. Sometimes paraffin, chemical colors, cement and tar have been used. Formerly even goat or other animal fat was used for this in Georgia. All these are gross violation of traditional winemaking technology and adversely affect wine quality.
The decision to wax a qvevri’s inner walls has to be made carefully, as qvevri winemaking technology usually implies the direct contact of the wine with the clay walls. Waxing is justified when qvevri walls are very porous. Highly porous qvevri allow wine to leak out or water to seep in. New, unburied qvevris as well as used qvevri which are already buried in the ground can be waxed, although it’s more difficult in the latter case.
Qvevri waxing is a complex process and should be performed by an experienced person. What is implied by “proper qvevri waxing” and what is the purpose of this operation? New qvevris are waxed as follows:Pure beeswax is placed in a clean vessel and melted at a temperature from 110 to 120 0C. This will cause evaporation and reduce the amount of wax. At the same time the qvevri itself is heated, placed on the ground on its side with a fire kindled inside. Ideally dried vine stalks are the best choice for making the fire. The use of plastic, rubber, coal, coniferous firewood or straw for kindling a fire should be avoided, and obviously the qvevri must not be heated with the aid of fuels such as petrol, diesel or a kerosene burner. It seems that using natural gas for heating qvevris is acceptable although it has not been tested sufficiently.The wax should be applied only when the qvevri has been completely and thoroughly cleared of ashes, soot and pieces of coal.
To prevent the qvevri walls from cracking, a weak fire is kindled first, and then gradually increased, and to avoid contamination from the remains of soot and coal the fire is kindled in a tin vessel placed in the qvevri. Overheated qvevri walls can crack or overheating can cause the wax to be burnt out or evaporate when being applied to the overheated walls.The temperature of the walls has to be lower as well. If not, melted wax will stick to the remaining ashes, soot or coals and then affect the wine’s bouquet and quality by the smell and taste of smoke.
To ensure that the qvevri walls are evenly heated it should be turned slowly with the fire burning, until all the walls are evenly heated to the desired temperature. This temperature can be determined by touching the outside wall of the qvevri. It should not be so hot as to burn your hand nor should it be only slightly warm.It is advisable that the qvevri be heated up to 70ºC. Such fire heating is especially advisable for old qvevris that have not been used for a long time as they often have dirt deeply ingrained in the walls. The fire burns it out and facilitates cleansing.
At this time the qvevri walls—and more specifically their pores--will easily soak up the melted wax and avoid the risk of wine seeping out. The wax is completely soaked up by the qvevri walls. This technique ensures a very reliable sealer for the porous walls of the qvevri.
To coat the qvevri interior with melted wax, the following technique is employed:
-a piece of cloth is fixed to a long stick. (This used to be known as a mola in Kakheti.)
-subsequently it is dipped into the melted wax, and
-then with circular movements of the stick in the qvevri, the walls are coated with the wax.
For a qvevri holding 1000 or 1500 liters, approximately 1.5 to 2 kg of beeswax is required, although this quantity may vary. Waxing starts from the qvevri bottom and proceeds upwards. Formerly this process was carried out with another technique: a large piece of wax was thrown in the qvevri which was then shaken, turned up, down and over until the wax was equally distributed on the walls. To wax a small-size (kotso) qvevri it would be placed in a heated traditional bread oven called a “tonne” or placed over a stanchion, a vertical pole, for heating. This is also an effective technique.
In such cases the qvevri is not contaminated with ashes, soot or coal. These techniques are equally justified for a large-size qvevri, which can be placed on its side on a special wooden beam with a fire kindled inside. It is then gradually rolled over so that its walls are equally heated. This heating technique is preferable to the first as it prevents the qvevri from becoming contaminated inside with ashes, soot and coal.
Older, buried qvevris can also be heated and waxed. First the qvevri is thoroughly washed and dried. Then a fire burning in a metal cylinder (with its top open and bottom closed) is lowered into the qvevri with a wire. The open end of the cylinder must protrude from the qvevri opening so the smoke doesn’t soot the walls. To ensure air for the coals to burn, the lower sides of the cylinder (but not the bottom) are pierced with small holes. Qvevrissubjected to thisprocedure arecleansed and ready for waxing.
Since waxing is meant to seal the principle and large-size pores, qvevri are frequently coated thickly inside. This renders them similar to enamel containers and the wine is in contact with the wax rather than with the clay walls, which means the qvevri’s special properties for wine fermentation and aging are lost. Excessive waxing is not justified with the exception of rare cases when qvevris are of substandard quality and making quality wine would be impossible without thorough waxing.
Recently, enamel qvevri lining has been introduced to Georgian qvevri which is also useful when substandard qvevris are used. However, some believe that wine fermented and aged in a qvevri coated inside with a thick layer of wax, or lined with enamel, cement, etc. can hardly be called “qvevri wine”, since qvevri winemaking comprises the direct contact of the wine with the clay walls. This is another reason that the best quality qvevri are highly desirable.
Another issue to be considered concerns the quality of wax. Artificial honeycombs used by beekeepers are arranged in beehive frames and in most cases plates contain paraffin, stearin and other wax-containing artificial additives. The best option for qvevri is wax extracted from wax capping with no man-made impurities. This wax is lighter in color than the wax extracted from the brood comb.
In some villages, for airtight wine storage, qvevris are first filled up with wine and then melted wax is poured on the upper surface of the wine. This has proven unsatisfactory, however for several reasons and doesn’t warrant the extra cost or the sacrifice of wine quality. Small temperature changes in the qvevri cause changes in the volume of wine and make it expand or contract. Wax applied directly on top of the wine will soon pull away from the qvevri walls and cause the seal to be broken. Another problem is that the melted wax is very hot and, although on the surface of the wine, it still warms all the contents of the qvevri, causing possible propagation of acetic acid bacteria in the wine. Acetic acid bacteria spreads from the wine’s surface towards the bottom of the vessel.
Formerly there was a custom to pour vegetable oil onto the wine’s surface to ensure airtight storage of the wine but this is also unadvisable since the oil becomes rancid and deteriorates wine quality. At the same time it fails to ensure airtight wine storage. The best way to ensure the airtight storage of qvevri wine is to properly seal the vessels with lids which are the right size rather than to pour oil, melted wax or other substances on the surface of the wine.