Sherry is an alcohol-added white wine of true quality and diversity that can be sweet or dry. Sherry-type wines remain undiscovered by most of the world. This helps keep the price of good Sherry attractively low.
The Palomino grape — the main variety used in Sherry — thrives only in the hot Sherry region of Spain, on albariza soil (the region's
famous chalky earth). Two other grape varieties, Pedro Ximénez (PAY dro he MAIN ehz) and Moscatel (Muscat), are used for dessert types of Sherry.
The phenomenon of flor
Sherry consists of two basic types (sweet Sherries are made by sweetening either type):
Fino (light, very dry)
Oloroso (rich and full, but also dry)
After fermentation, the winemaker decides which Sherries will become finos or olorosos by judging the appearance, aroma, and flavor of the young, unfortified wines. If a wine is to be a fino, the winemaker fortifies it lightly (until its alcohol level reaches about 15.5 percent). He strengthens future olorosos to 18 percent alcohol.
At this point, when the wines are in casks, the special Sherry magic begins: A yeast called flor grows spontaneously on the surface of the wines destined to be finos. The flor eventually covers the whole surface, protecting the wine from oxidation. The flor feeds on oxygen in the air and on alcohol and glycerin in the wine. It changes the wine’s character, contributing a distinct aroma and flavor and rendering the wine thinner and more delicate in texture.
Flor doesn’t grow on olorosos-to-be, because their higher alcohol content prevents it. Without the protection of the flor (and because the casks are never filled to the brim), these wines are exposed to oxygen as they age.
Communal aging
Both fino and oloroso Sherries age in a special way that’s unique to Sherry making. The young wine is added to casks of older wine that are already aging. To make room for the young wine, some of the older wine is emptied out of the casks and is added to casks of even older wine. To make room in those casks, some of the wine is transferred to casks of even older wine, and so on. At the end of this chain, four to nine generations away from the young wine, some of the finished Sherry is taken from the oldest casks and is bottled for sale.
This system of blending wines is called the solera system. It takes its name from the word solera (floor), the term also used to identify the casks of oldest wine.
As wines are blended — younger into older, into yet older, and eventually into oldest — no more than a third of the wine is emptied from any cask. In theory, then, each solera contains small (and ever-decreasing) amounts of very old wine. As each younger wine mingles with older wine, it takes on characteristics of the older wine; within a few months, the wine of each generation is indistinguishable from what it was before being refreshed with younger wine. Thus, the solera system maintains infinite consistency of quality and style in Sherry.
Because the casks of Sherry age in dry, airy bodegas above ground (rather than humid, underground cellars like most other wines), some of the wine’s water evaporates, and the wine’s alcoholic strength increases. Some olorosos aged for more than ten years can be as much as 24 percent alcohol, compared to their starting point of 18 percent.