Before distillation, Peruvian pisco grapes are first crushed and then fermented to make wine. It is very important to make precise decisions about when to harvest so the grapes have the right amount of sugar, acidity and tannins. Having this balance gives us high-quality wine and pisco. Nati uses both science and intuition to determine if this balance has been achieved.
First, science is used to determine the sugar and pH levels. Nati uses specific measurements to determine that the Brix levels of our Quebranta are between 24°-26° and our Italia between 22°-23°. It is important to obtain the right amount of sugar because yeasts need glucose to convert the juice into wine. Furthermore, as grapes ripen, acidity drops as sugar levels increase. However, we need to maintain certain levels of acidity so the wine is well-rounded. Nati strives for a pH of around 3.2-3.4.
Nati also checks for physiological changes in the vines. This means that the grapes, stems and seeds have the proper coloring. The fruit should be bright and robust and the stems and seeds should be brown, indicating they are ripe.
Finally, she uses intuition when tasting the fruit. The fruit must taste sweet and have good acidity and tannins. Sugar is especially key in pisco production; the more you have, the higher the alcohol content.
Determining when to harvest is an extremely important step in the pisco production process. Perfecting the balance of science and intuition gives us grapes with better flavors and aromas and thus, a well-rounded pisco.