This is the 11th in a series mythbusters to clarify misconceptions about Peruvian pisco!
Quebranta is indeed a very flavorful variety, but so are the other 7 Peruvian pisco grapes.
Let’s first address the idea that the Quebranta grape is the strongest of all the Peruvian pisco grapes. This statement brings up a lot of questions, such as: What does “strength” refer to? Does it refer to the strength of the flavor of the Quebranta grape? Or perhaps it refers to the robustness of the Quebranta plant? Or maybe this is a misconception of the alcoholic strength of the final product?
The Quebranta plant is Peru’s only indigenous vitis vinifera variety and it has indeed adapted very well to the climate and soils in Peru. However, from a standpoint of durability or longevity, the Negra Criolla (Listán Prieto) variety was the first to be planted in Peru sometime between 1539 and 1541. Therefore, because Negra Criolla has been around for longer in Peru, it would technically win the contest of longevity.
Furthermore, potency of the alcohols in a pisco depend not on the grape type, but on the sugar levels of the grapes used in fermentation. We all know that a pisco can have a maximum ABV of 48%. You can have pisco at 48% ABV made from any of the 8 grapes allowed in the production of Peruvian pisco, not just Quebranta. To reach the desired sugar levels, and therefore the desired alcohol levels of the final product, vintners will aim to reach around 23-26 Brix before harvesting. This measurement is taken with a refractometer. Then finally, proper distillation methods also help regulate the alcohol content.
Second, it is difficult to defend or refute the notion that Quebranta is the most flavorful grape because the concept of taste is very subjective. What may seem flavorful to one person could be bland to another. It would require years of qualitative research and surveying to determine which grape is the most flavorful.
Making scientific measurements of flavor requires the implementation of complicated processes. Techniques such as solvent extraction and headspace methods would be required to identify and qualify methoxypyrazines and non-volatile, glycosylated conjugates of volatile molecules in grapes, among many other elements. Then to analyze, one would need to conduct gas-liquid chromatography and mass spectrometry. Furthermore, soil, climate and traditions also greatly impact flavor expression, regardless of the grape variety. All of those factors would need to be studied and compared before making a general statement about the flavor of Quebranta grapes.
Put simply, the most flavorful pisco grapes are the ones that have been tended to carefully throughout the year and the whole production process. Those grapes are most flavorful when they are recently harvested and have the desired Brix levels. Needless to say, it is a very weak argument to say that the Quebranta grape is the strongest and most flavorful grape without any data or research to back it up. In our opinion, all the Peruvian pisco grapes are strong, flavorful and so unique that they should each be appreciated as such.
Williams, P. J., and M. S. Allen. “The Analysis of Flavouring Compounds in Grapes.” SpringerLink, Springer-Verlag, Berlin, Heidelberg, 1 Jan. 1996, link.springer.com/chapter/10.1007/978-3-642-79660-9_3.