All true Sherry fortified wine comes from the vineyards around Jerez de la Frontera and the nearby coastal towns of Puerto de Santa Maria and Sanlúcar de Barrameda. Together these three towns form the three points of the 'Sherry Triangle'. The Jerez DO (Denominación de Origen) title was Spain's very first, awarded in 1933.
Palomino Fino is the principal grape variety, used for Fino, Manzanilla, Amontillado and Palo Cortado wines. Pedro Ximenez and Moscatel de Alejandria are used for sweeter styles.
Flor and Principal Dry (Generoso) Sherry Categories
Once a base wine is fermented, each tank is assessed and it’s decided whether the wines will be aged with or without flor. Wines categorised as palo (stick) are marked with a vertical slash, fortified to ~15%, and earmarked for Fino or Manzanilla. Mitad y mitad (half and half) is a fortification mix of spirit and aged Sherry. Fino and Manzanilla undergo biological aging under flor del vino (flower of wine). The normal yeasts for alcoholic fermentation die as sugar is consumed in base wine production. But then a specialised group of ambient yeast species appear, forming a film on the liquid surface. This layer protects the wine from oxidation while metabolizing glycerine, alcohol and volatile acids. For it to form, humidity, airflow, temperature all have to be correct, as does the alcohol level of the wine.
Other base wines are fortified to ~17.5%, classified as gordura, and marked with a circle. This level of fortification means that flor cannot develop. The wines undergo oxidative aging only, and will become nutty, rich Oloroso Sherries.
Fino wines are more delicate and almond toned, with a salty tang. They have a final alcohol by volume of 15% to 18%. A Fino ages under a protective layer of flor, but with extended aging the flor may disappear and the wine begins to oxidate, taking on nutty character. A Fino-Amontillado bottling may result, but otherwise the process continues and results in a full Amontillado. Such wines will have a final alcohol level between 16% to 22%. Because Fino and Manzanilla are aged under flor, they have typically been heavily fined and filtered to remove yeast and other sediments.
Recently en rama wines have become popular. These are bottled with no or minimal filtration, and are an intense, fuller bodied wine, closer to a cask sample.
Palo Cortado (cut stick) Sherries start life aging under Flor. But the richness of the wine leads the cellar master to fortify again to around 17%. This kills the flor and the Sherry finishes maturation in the style of an Oloroso. The finished wine combines the richness of Oloroso and the delicate aromas of Amontillado.
Sherry may be bottled direct from the Solera as a Generoso, but many Sherries are sweet blends. Dulce Pasa – sun dried Palomino Fino grapes – are the most common sweetening agent. Pedro Ximénez is more expensive and so tends to only feature in pricier wines. Pale Cream is essentially a sweetened Fino. Cream is a sweetened Oloroso – and sometimes labelled as Oloroso Dulce. A Medium Sherry may include some Amontillado. Confusingly, a generic Dry Sherry will also have been sweetened to some degree.
Few Sherry wines are vintage releases. Instead a blending system known as a Solera is used. New wines are placed in a top tier of butts (casks) known as the criadera. At the other end of the Solera is a tier of butts called the solera, from which wine is removed for bottling. There may be anything from three to 14 criadera tiers feeding the solera butts. Only one quarter of the Solera butt may be drawn off at one time. It is then topped up by the "lowest" level of criadera butts, which in turn are topped up from the above tier. In this way the solera – in theory at least – continues indefinitely with a (diminishing) portion of original wine. Sherry wines are often given an age statement which is based on when the solera was started.