Geometry and Wood Origin of Barrel Alternatives: Impact on the Chemical Composition of Aged Tsipouro

This study investigates the impact of wood origin and the geometry of barrel alternatives on the extraction of volatile compounds and total ellagitannins during the aging of tsipouro, a traditional Greek spirit. French, American, and Greek oak, along with Greek chestnut, were used in the form of veneers, sticks, and particles to simulate aging conditions. Volatile compounds were analyzed using gas chromatography–mass spectrometry, while ellagitannin levels were determined by high-performance liquid chromatography with diode-array detection after acidic hydrolysis. A total of nine volatile compounds were identified, with significant differences (p < 0.05) observed based on wood type and fragment dimensions. French oak exhibited higher concentrations of vanillin, syringaldehyde, sinapaldehyde, and coniferaldehyde, while Greek chestnut showed notably lower levels of these compounds. However, chestnut wood yielded the highest ellagitannin concentrations (up to 17.84 mg/L), whereas Greek oak exhibited the lowest (0.20–0.60 mg/L). Veneers (wood sheets) were generally more efficient than sticks or particles in compound extraction. These findings indicate that both the botanical origin and physical dimensions of wood fragments play a crucial role in shaping the chemical profile of aged spirits. Furthermore, the results highlight the potential of Greek woods as sustainable, economically beneficial alternatives in modern aging practices.