About Sherry – In Depth

The whole nature of Sherry depends on the Solera system. Each house has its own brands and styles. The job of the wine maker is to ensure that those styles are continuous so that the consumer always gets consistent style and quality whenever he or she buys a bottle of that wine. Following is an in-depth account of how the Solera system works and what is involved for the wine maker.

The Solera system is the method used in the production of Sherry to ensure a consistent quality, based on the fact that old wine can be refreshed by the addition of a younger wine, which then acquires the characteristics of the old wine. It is a traditional form of fractional blending.

The Solera system consists of a stock of wine in butts, split into graduated units each of a different maturation development and each of equal volume. The final stage of finished wine is called the solera. The supporting steps, or scales, are called criaderas. Wine for blending is drawn from the solera, which is replaced by wine from the immediately supporting criadera of wine of the same style, a little younger and less complex. From there, replacements proceed in succession down the scales of the system until the youngest criadera is refreshed with carefully selected wine from a suitable añada stock. There can be differences in the number of scales from start criadera to solera. This is largely dependent on the style of the finished wine. Soleras of very old quality wines will be refreshed from other mature soleras of similar styled wines but not from añada stock.

When wine from the oldest casks of any one solera is withdrawn for bottling - usually between 10% and 15% of the wine in any one 550 litre cask - the same amount of wine is removed from an equivalent number of the casks of the first criadera or nursery. This wine is then blended and added in equal proportions to the space left in the casks of the solera. During the course of the following months - the period may be anything between 3 months and 2 years depending on the age and concentration of the wine - the slightly younger wine amalgamates with and takes on the characteristics of the majority older wine and eventually becomes homogenous with it. All the wine in the cask becomes exactly the same as the wine which was taken out months previously.

At the same time wine is taken in the same quantities from second criadera, blended together and added to the space left in the first nursery. The same homogenisation process occurs. From the third nursery, wine moves to the second and so on, until the youngest nursery is reached. This is then refreshed with young wine in añada which is showing the style characteristics of that solera.

There are a couple of points that need to be noted about the Solera system. Firstly, the whole system from the youngest criadera to the end is known as a Solera, whilst the oldest wine in it is the Solera. It is not usual to withdraw wine from every barrel in a Solera at any one time. The amount of wine withdrawn, and thus the number of butts affected, will depend precisely on the amount required for bottling. Secondly, these bodega butts of 550 litre capacity are only filled to 500 litres, to allow the circulation of air needed to help the flor work, or to encourage oxidation in the case of Amontillado and Oloroso. There is a restriction on a bodega's throughput set by law. Each bodega may, in one year, withdraw for sale or shipment a maximum of 35% of its total stock. Buying in wine at any stage of maturation to increase the size of their Soleras is quite usual, as demand for a particular style grows. Conversely, selling stock for the opposite reason is also quite normal.