Corvina, with its thick skin and robust structure, is ideally suited for the Appassimento process. The grape's inherent characteristics, such as its medium size and the natural waxy coating, make it resilient enough to withstand the drying period without losing its vital acidity or succumbing to rot.
The Drying Process
Selection and Harvest: The Appassimento process begins in the vineyard with the careful selection of grapes. Only the healthiest bunches of Corvina are chosen, typically harvested slightly earlier than usual to retain higher acidity levels.
Drying Facilities: The selected grapes are then placed in specialized drying facilities, known as 'fruttai.' These airy, well-ventilated rooms allow for a slow and controlled dehydration of the grapes.
Time and Patience: The drying period can last from several weeks to a few months, depending on the desired wine style. During this time, the grapes lose up to 30-40% of their water content, concentrating their sugars, flavors, and acids.
Impact on Wine Characteristics
Concentration of Flavors: As the grapes dry, their flavors become more pronounced and complex. The reduction in water content concentrates not just the sugars but also the acids and tannins, creating a rich and robust flavor profile.
Aroma Development: The process also affects the aromatic compounds in the grapes, leading to the development of unique dried fruit, spice, and nutty aromas that are characteristic of Appassimento wines.
Alcohol and Body: The increased sugar content results in higher alcohol levels post-fermentation. Wines made through Appassimento are generally fuller-bodied, with a luscious, velvety texture.
Enzymatic Activities: The drying process activates various enzymes within the grape. These enzymes, particularly those involved in phenolic and aromatic compound development, play a critical role in defining the wine's flavor and color profile.
Phenolic Compounds: Enzymatic reactions lead to changes in phenolic compounds, including tannins and anthocyanins. These compounds are responsible for the wine's structure, color stability, and aging potential.
Aroma Compound Development: The breakdown of certain compounds and the formation of new ones contribute to the development of unique aromatic profiles, such as dried fruit, tobacco, and spice notes typical of Appassimento wines.
Acid and pH Changes
Acid Concentration: The drying process also concentrates the acids present in the grapes, notably tartaric and malic acids. This concentration is essential to balance the increased sugar levels and to maintain a fresh taste in the final wine.
pH Stability: Despite the concentration of acids, the pH of the grapes remains relatively stable, which is important for preventing microbial spoilage during the drying process and subsequent fermentation.
Post-Drying: Preparation for Fermentation
Rehydration and Pressing: After drying, the grapes are often rehydrated to facilitate pressing and extraction.
Slow Fermentation: The high sugar content leads to a slower fermentation process, as yeast works to convert the sugars into alcohol. This prolonged fermentation contributes to the development of complex flavors.
Influence of Environmental Factors
Temperature and Humidity Control: Maintaining optimal temperature and humidity in the fruttai is crucial to prevent mold growth and to ensure even drying.
Ventilation: Adequate air circulation is vital to remove the moisture released by the grapes and to prevent any fungal development.
The Appassimento process is a remarkable blend of art and science, where controlled natural drying leads to profound chemical and enzymatic transformations in the grapes. These changes are fundamental to creating the rich, concentrated, and complex profile of wines like Amarone. Understanding these processes not only highlights the sophistication of this traditional winemaking technique but also underscores the importance of meticulous control at every stage of production.