These special marks made upon the casks in chalk or white paint have different meanings. When the marks are painted arrows they usually refer to the content of the cask and of those around it. When the marks are made with chalk they usually refer to the content, once measured, to comments made by the taster or tasks which need to be carried out on a particular cask.

This is extremely difficult to gauge. The casks are hardly ever moved from place and in the case of Sherry Wine: the older the wood, the better (the longer a cask has been steeped in sherry, the greater its value). We may therefore state that such casks are almost eternal. It is, however, frequently necessary to replace one or two staves if a leak has been detected. In this case the cask is emptied, removed from the andana and repaired in the cooperage, where wooden staves and other parts are replaced as deemed necessary.

In the case of biologically aged sherry, the particles of flor which die off and fall to the bottom of the cask form a sediment there known as the mother of the wine. Some firms choose to remove this sediment, in which case they need to extract the wine and clean the cask, whilst others leave it in place as the sediment also contains minerals and other elements which enhance the bouquet of the wine. If the latter be the case, then those casks are never cleaned. Quite different would be the case if the sherry within a particular cask has turned to vinegar or has been contaminated by some unwanted aroma, in which case it will be necessary to disinfect the cask before it can be re-used

Apart from decorative reasons, the black paint known as caparrosa with which the casks are usually painted also has a practical use. Being matt black it is easier to spot leakages from the cask, as leaking sherry shines bright upon the matt surface of the cask.

The microclimate of the Jerez region means that despite the way in which bodegas are insulated from the exterior, the liquid contained in the casks suffers a high degree of evaporation in the interior of the bodega; somewhere in the region of 3 to 4% of their content each year (what the French refer to as the angels share). This evaporation basically consists of water and to a lesser degree wine alcohol, but along with these elements other aromatic components are also released and these are responsible for the intense aroma.

The day to day work in the bodega, transferring wine from criadera to solera, naturally causes the film of flor to break. We try to ensure that any gaps produced in the film are as small as possible, and in fact special tools have been designed with this goal in mind, such as the .rociador. (a curved tube with holes punched in it used to pour wine into the cask). Furthermore, the flor, in its attempt to cover the whole surface of the wine as it reproduces, will only take a few hours to cover up any such gaps and thus protect the sherry from oxidation.

Logically many of the jobs which used to be done using muscle-power are now carried out by machines, such as the construction or dismantling of an andana. Likewise the transfer of wine from criadera to criadera used to be done manually using large jugs, whilst nowadays a system of pumps and pipes connected to the casks are used in order to perform the corresponding sacas and rocios (insertion and extraction). But the essence of the work remains unchanged: the very same processes are still in use, albeit with the help of modern equipment which technology has placed at our disposal. Nothing, however, can replace the work of the tasters or the need for the wine to spend years ageing within the cask in order to acquire its definitive characteristics.

There has been a progressive use of mechanical harvesters to collect grapes in the Jerez Region. However, over 90% of the grapes are still picked by hand. Besides, quality assurance testing carried out by the Consejo Regulador upon musts produced from both hand picked and machine-picked grapes have been unable to identify any significant differences. The key factor is always that of the speed and the care with which the grapes are transported from the vineyard to the pressing machines. Another factor to take into consideration is the height of the vine, which must be greater if machines are to be used for picking, and this must be foreseen in the first few years after the vine has been planted.

No, it is prohibited to water vines. However, in the case of newly planted vineyards or in the face of any possible risk of vine loss in times of drought, the Consejo may issue special licences which are strictly controlled. Vines planted in good albariza soil benefit from the high humidity retention capacity so characteristic of this type of soil, which means that any widespread authorisation to water vines could lead to vineyards being planted upon less suitable, though perhaps more productive, land.