In Peru, the preparation of pisco begins in March each year with the harvest of carefully selected grapes from the coastal vineyards. Baskets of grapes are loaded in trucks, weighted, and unloaded in a rectangular masonry presses (“lagares”) that are necessarily located in the highest point of the cellar. From there, juice and musts will flow due to gravity, first into fermentation tanks and then to the still itself. Seven kilos of grape produce one liter of pisco.
“Grape stomping” generally begins at dusk, avoiding the tiring heat of the day, and lasts until daybreak. A team of six “stompers” or threshers spread the grapes into the presses. Between songs and jokes, threshers do their job while drinking “chinguerito", a punch made from the same fresh grape juice they are squeezing, an adding a good portion of pisco, lime, clove and cinnamon.
After the sixth threshing, the press gate is opened and the fresh grape juice falls into a deposit (puntaya), where it is stored for 24 hours. After that, the juice is taken to fermentation tanks through an ingenious channel system. Current cellars use garrotas (presses), grape mills and pneumatic presses, transforming the traditional stomping process in a highly efficient mechanized system.
An biochemical process of alcohol fermentation occurs in the tanks, where the glucose contained in the grapes’ natural sugar becomes pyruvic acid and forms an ester, which losses carbon dioxide when releasing the carboxyl functional group of pyruvic acid through a biological mechanism typical of yeasts. The produced ethanol later accepts two protons from the NADH and the one released in the initial glycolysis stage, turning into ethanol or alcohol for human consumption.
This is achieved through small natural yeasts contained in the fruit skin which digest one gram of sugar and transform it into half a gram of alcohol and half a gram of carbon dioxide. The process takes seven days. The producer checks the fermentation for any interruption to the process, and controls that the must temperature is not too high as the fruit may lose its natural aroma, which gives pisco its characteristic touch. When fermentation is concluded, the liquor is taken through the channels to the still, where distillation begins.
The distillation technique and art consists in regulating the heat supply to achieve a low and constant rate that permits the generation of the desired aromatic components in the right moment. The process has two stages: vaporization of volatile must elements and condensation of vapors.
The sole areas recognized as producers of pisco are the coast of the regions of Lima, Ica¬¬—where the Pisco Valley is located—Arequipa, Moquegua, and the valleys of Caplina, Locumba and Sama, in Tacna.
A valley, a river, a port and a city located in the Peruvian coast have been known as Pisco since ancient times. These sites even appeared in a map of Peru made by Diego Mendez in 1574.
In the mid 19th Century, Peru had planted almost 150,000 ha of vines for pisco production. This production level decreased gradually until reaching 11,500 ha in year 2002, due to a lack of incentives and the substitution of crops for others that bore greater short-term profits.
After verifying the decline of this ancestral crop after almost four hundred and a half centuries, and aiming at progressively recovering previous production levels, in early 2003 the Peruvian Government decided to promote the increase of grape growing areas and pisco exportation, enacting the corresponding special measures.
At the same time, specific and strict legal mechanisms were issued, to allow producers to reach a high quality level, disqualifying those who failed to meet the basic requirements of obtaining a top-class liquor, even prohibiting them from exporting the liquor under the name "pisco”.
Current sown hectares produce some 800,000 liters of pisco per annum. In 2007, the main export destinations were: the United States, France, Spain, Germany, Canada, Colombia, Mexico, Argentina, Australia and the Czech Republic.