L'THE IDEA BEHIND TAVA'S CLAY BODY
There are different types of ceramics that can be used for manufacturing amphorae or wine vessels, however their diffusion within wineries has remained rather limited over time.
This is because - as we will see shortly - each of these materials has advantages and disadvantages when used in the oenological sector. For this reason, over the years, Tava has developed an exclusive ceramic body mixture that has all the characteristics required for high quality winemaking.
THE OTHER MATERIALS THAT CAN BE USED IN THE ENOLOGICAL SECTOR
The term ceramic (from the ancient Greek “Kéramos” which means clay) refers to an inorganic, non-metal material that is very ductile in its natural state and becomes rigid after the firing phase. Ceramic is usually composed of different materials: clays, feldspars (sodium, potassium or both), silica sand, iron oxides, alumina and quartz.
This structured composition results in the presence of flattened molecular structures called phyllosilicates. The shape of these structures gives the clay a certain plasticity when combined with water and allows it to be processed more easily and effectively.
Typically reddish brown and characterized by a firing process that ranges from 960°C to 1040°C terracotta is traditionally used for the production of floor tiles and tableware. Most of the jars, barrels and amphorae for oenological use are made of terracotta.
Pros: very malleable during production, low cost, low firing temperature (resulting in reduced energy costs).
Cons: high porosity which results in a very marked permeability to oxygen with relative oxidative phenomena of the contents. High porosity also leads to increased difficulty cleaning and sanitizing as the contamination is easily trapped in the porous surface.
Used for the production of tiles for bathrooms and kitchens, it is characterized by firing at temperatures ranging from 1200°C to 1350°C. Its main feature is the substantial absence of porosity. White stoneware is made of artificial mixtures based on white firing clays and quartz-feldspathic rocks which cause the vitrification of the body. In recent years this material has been used for the production of stoneware barrels for oenological use.
Pros: very high physical resistance, ease of automated processing, can be easily cleaned and sanitized.
Cons: the low porosity leads to very low redox exchange (essentially insignificant) for example in comparison with the redox exchange of wooden barrels, the exchange in stoneware is reduced by about eighty - ninety percent.
Porcelain was invented in China around the Eighth Century and is made with kaolin, silica (or quartz sand) and feldspar. Kaolin often confers the typical plastic properties and the white color of porcelain; quartz is the inert component acting as a degreaser (in addition to enabling vitrification); finally, feldspar, used as a fluxing agent because, by melting at lower temperatures than kaolin, it significantly lowers the firing temperature of the clay body (1280°C). There are very different types of porcelain, depending on the different production traditions.
The use of porcelain for wine vessels is very rare since porcelain is a material with characteristics similar to glass.
The firing temperature of clay varies according to the Alumina content. Clay is naturally very malleable, since the presence of water in its structure improves its plastic properties and it is therefore very easy to work, even with the hands. When it is dry, but has not yet undergone the firing process, it is stiff and brittle. When subjected to intense heat, it becomes permanently solid and strong.
TAVA'S EXCLUSIVE MATERIALS
The material with which Tava’s amphorae are made is the result of the collaboration between experts in the production of clay bodies, oenologists and wine producers. This close collaboration, aimed at finding materials that can best meet the needs of wineries, has allowed us to develop, after years of field experimentation, a particularly suitable clay body mixture.
The mixture created by Tava, in short, has only the best characteristics of the ceramic materials already used in the oenological field, and eliminates all the drawbacks that have slowed its diffusion in the winemaking industry.
More specifically, our amphorae are fired at temperatures ranging from 1200°C to 1260°C. This heat treatment gives the ceramic specific oxygen permeability values, which can vary from levels slightly lower than those of wood up to the total absence of redox exchange, depending on the porosity requirements indicated by the cellars. The control of porosity levels also ensures that the cleaning and sanitizing processes are effective and simple, since the liquid is only able to contaminate the surface of the ceramic material. The third characteristic of our ceramic body mixture is its high thermal insulation capacity, even higher than that provided by concrete. This peculiarity enables the contents to be perfectly insulated, maintaining a constant temperature over time.
Controlled
porosity
The porosity of the clay is a key element for the winemaking process in an amphora. In fact, porosity can be adapted to the specific requests of the winery.
Thermal
insulation
Ceramic materials ensure superior thermal insulation than concrete with the same thickness.
Cleaning and
sanitizing
As a result of specific manual finishing, our amphorae are extremely easy to clean and sanitize.
