Pisco is a brandy made originally from the fermented juice of the Quebranta grape, a Muscatel variety that grows in the Ica region of southwestern Perú and in the Elqui valley of Chile (left, formerly part of southern Perú).
Popular legend traces the origin of pisco to an ancient Incan ceremonial alcoholic beverage. This is inaccurate (the Incas never grew grapes), but it is certain that the recipe is over 400 years old. The only alcoholic beverage attributed to the Incas was chicha, technically a beer (sour mash) made from corn. The corn was mashed and fermented in a clay vessel buried in the ground. The Quechua (the prominent Inca tribal group) word for the clay vessel is pisco*.
The Spanish brought Muscatel and winemaking to South America, and with it the distilling of wine into aguardiente (brandy). The Muscatel, a dark, aromatic, high-sugar grape, was grown in Europe primarily for making raisins, sweet wines, and brandy, and the Spanish began making aguardiente from Muscatel wine in the Viceroyalty of Perú (Perú and Chile today) as early as 1547. They found that the arid, sun-drenched valleys pictured here, irrigated with pure Andean snowmelt through Inca engineering, was a superior environment for viniculture. The grape pressings were fermented in the same clay pots used to make chicha. Hence the name pisco. The Chilean poet Pablo Neruda called pisco "bottled sunshine."
Today the grape pressings are fermented in steel vats, not clay pots (except in Perú). The resulting wine is then distilled in copper stills, cooled, and (for pisco corriente) blended with purified water to reduce the alcohol content. The process is similar to the production of grappa in Italy.
In Perú, the production of pisco is highly regulated, in contrast with Chile, where regulation is minimal (except for appellation designation), and standards are set by industry association. Export-grade Peruvian pisco is never blended with water or anything else which could disallow the appellation of pure pisco. In Chile, some grades are aged in oak casks prior to bottling, while in Perú, the casks are lined with paraffin to keep the liquor clear and complex flavor pure. (Unlike whisky, pisco doesn't benefit significantly from aging, but does soften somewhat.) In Perú, where Quebranta vineyards are rapidly disappearing, regulations have expanded the appellation region and permitted the limited use of non-aromatic Common Black or Mollar grapes. Chilean producers may use Quebranta or a variety of several other Muscatel cultivars.
Peruvians and Chileans happily enjoyed pisco "straight" for 400 years. However, it was too potent a beverage for many visitors who drank it either diluted with water or mixed with fruit juices. Probably one of the oldest recorded cocktails is the Pisco Punch, which was served aboard steamships stopping in Chile en route to San Francisco. Pisco Punch was essentially a Pisco Sour served with a splash of pineapple juice and mineral water.
Chilean pisco is sold in 645ml and 700ml bottles. The best brands are sold in the 700ml size. The alcoholic content will range from the 35% (70 proof, diluted with purified water) corriente or especial up to the 50% (100 proof) gran pisco. The clear corriente is the grade most produced and consumed in Chile, and is used for Pisco Sours or other pisco cocktails (such as Piscola, which is pisco and cola, and Cola de Mono) but rarely sipped. The pure reservado, at 40%-45% potency, is excellent for mixing as well as sipping neat. The pure, amber-colored gran pisco, which has wood-aging flavor imparted to it, is used strictly for sipping. The gran pisco can cost more than twice as much as the corriente.
Peruvian pisco grades include the acholado ("half-breed"), made from any of a variety of grapes, the aromático, made only from Muscatels, and the puro, made primarily from Quebranta grapes. The pure pisco is the only grade exported in any quantity, and is of consistently high quality. At around 42% alcohol, it may be mixed, served on-the-rocks, or sipped. It is drier and more aromatic than most Chilean piscos.
You may have trouble finding pisco in the U.S., except in a major liquor store in a large Eastern Seaboard city. Many stores (especially in Canada) may sell only Peruvian pisco, but the Peruvian pisco industry is contracting due to heavy duties on imported distilling equipment and the steady loss of Quebranta vineyards (caused mainly by water pollution from the mining industry). The Chilean pisco industry continues to grow, not only to meet domestic consumption, but also to meet increasing demand from Europe, Japan, Canada, and the U.S.
*Pisco is also a Quechua name for a sea bird common in Perú. The clay vessel was invented by a Quechua people called "Piskos".