TLDR

What is the solera system?

The solera system consists of barrels arranged in rows one above the other, to allow cascading racking. Used for making and aging wines, this consists of forming rows of butts stacked one on top of the other, forming a kind of pyramid that can be up to three heights. Each barrel is filled with wines from different vintages. The wine in the barrels closest to the ground will be the oldest, called "Solera" and the youngest called "criaderas" are placed on top of it.

The Long Read

The solera system is a method of aging and blending liquids, such as wine, beer, and spirits. It involves the continuous blending of older and younger batches of the liquid, resulting in a consistent flavor profile from one batch to the next. The solera system is commonly used in the production of sherry, port, and other fortified wines. The oldest part of the blend, known as the “solera,” is kept in barrels, and each time a portion of the liquid is removed for bottling, it is replaced with an equal amount of younger liquid from the next oldest barrel. This process continues until the youngest barrel is used to replace the liquid in the solera, starting the cycle anew. Despite constant reference to this system within the whisky world it is important to understand that these solera casks are not used for whisky maturation. By law, sherry must reach an average age of two years before it can be sold though most are far older than this.

The Solera and Criaderas method

The Solera method is more precisely called the Solera and Criaderas method. This method of fractional blending ensures that every bottling contains a small amount of much older liquid as only one third of the bottom solera cask is removed for bottling, this cask is then topped up from the first criadera (the next oldest), which is then replenished using the second criadera and so on until the last which will be refilled using wine from the latest harvest, named sobretabla. Because the level is restored with wine from the upper layers this maintains the development of the Flor, the layer of yeast that forms on the wine during maturation and that limits its oxidative development. This process of filling the barrels from criadera to criadera is called rocío. The exact number of barrels stored vertically varies but is usually three. Any more than five is totally unfeasible because the weight of the sherry butts above would end up breaking the lowest barrels.

One of the reasons why this system is used is because of the homogeneity that is created by mixing the different productions, making this product as similar as possible year after year. At the same time, they ensure that the youngest wines or spirits provide the greatest number of nutrients necessary for the yeasts. But it will always be the oldest product (Solera) that will be used for final consumption.

Characteristics of the system

The advantages of the Soleras method are evident, since the produced wine will be of constant quality, and mediated between the different vintages present in the barrel complex and between the different batches of elaborated wine that are added to the last from time to time criadera . By blending more vintages, the differences between them will be mediated and After a certain number of years, the bottled wine will maintain a constant average age.. New wines are gradually introduced into the system and their influence disappears as they quickly acquire the characteristics of the older product.

In the case of generous wines made with the Soleras method, the role performed by a master whisky blender is performed automatically by the solera, which amalgamates the batches and the individual vintages, obtaining a final product resulting from its assembly. In addition, the Soleras method is essential for biological aging in Flor since each addition of young wine provides the necessary micronutrients to sustain the yeast, which would otherwise die and the sherry would continue to mature oxidatively. To summarize, the Soleras method is essentially an infinitely precise and dynamic aging system. Once fully operational and properly maintained, it will produce a wine with a unique personality, the solera identity .

The process of transfer

The main drawback of the Solera and Criaderas method occurs when it comes to mixing the different wines, this was traditionally a manual job that requires unracking and reracking. The barrels generally have a capacity of about 5-600 litres so are not exactly light! Happily today there are automatic pumps equipped with multiple manifolds, called octopus, which allow the collection of precise amounts of wine at the same time from different barrels. The decanted wine is never poured directly from above, but is introduced into the barrel gently and always under the film of flor, without damaging it.

The age of the wine

It is impossible to accurately determine the age of a wine aged in a solera, such as a blend of many vintages. It depends on the number of criaderas, from the percentage of each butt and the frequency of removal. A wine of a solera started ten years ago, it will have a ten-year-old wine mixed with nine, eight, seven year old wine, until the last vintage. Besides the fact that the highest criadera is full of young wine, it does not mean that it is from the latest vintage, but it could be already mature wine, brought to a certain state of aging outside the solera. In this way, the solera can also be, so to speak, “expanded”. In the case of Jerez Las soleras you rarely start from scratch, most of the time you start with existing wines.

For this reason the product that is bottled can also never carry the “vintage” label since it will always be mixed with another, younger wine.

Brief history of the Soleras method

It is believed that the Soleras method of dynamic aging was born in Sanlúcar de Barrameda, a town near Jerez, in the second part of the 18th century, probably around 1760. Prior to its development, all sherries were bottled as vintages or aged wines. Initially it was simply a matter of blending wine from the previous vintage (called vino añejo) with the new production, but this gradually evolved into a more complex blending system of statically aged wines of different ages. The Solera and criaderas system as we know it today, it dates back to the 19th century and its final development coincides with the development of the use of Flor. Some historical Soleras back to the appointments in order from the 700 are still in operation, although in any case none of the original barrels may have survived, being a dynamic system that also implies the rehabilitation and progressive replacement of the “exhausted” barrels. Claiming these are the same soleras poses an interesting alternative frame for the Ship of Theseus thought experiment. In the past it was common to put the year of foundation of the Solera on the label, but this practice has now been abandoned as it tended to mislead the consumer.

The Soleras method in the world

Initially the Soleras method was used in Spain and Portugal for the aging of liqueur wines such as Sherry and Port. This method of dynamic aging, made famous by Sherry, is not really an exclusive idea of ​​Spain or Portugal however. It was also adopted in Sicily for Marsala. A rather similar system is used to produce fortified wines. Banyuls in the southwestern region of France and is called Sostrera. In Greece, the Soleras method is used to make a red dessert wine obtained from fortified Mavrodafni wine, produced in the northern Peloponnese. In South Australia some fortified wines similar to tawny Ports are created this way with blends of Shiraz, Grenache and Mourvedre. Back in France, some Champagne makers use a method similar to Soleras, called Perpetual to blend base wines for non-aged Champagne. In the United States, the producer Ficklin di Fresno (California) has been producing Port Wine using the Soleras method since 1948. The Soleras method is also used for distillates such as Brandy and rum. In Japan ’s Awamori, a particular type of sake is produced using a system conceptually similar to soleras, called shitsugi. Finally, in Sweden the Soleras method has been used since the 17th century to produce a sour beer, known as “hundraårig öl” (centennial beer), this is rarely commercially available however being mainly brewed at home for private consumption.