Effects of acid treatment on microbial stability and volatile profiles of apple distilled base wine

Microbial stability and volatile profiles are critical for distilled base wine quality. This study investigated how lactic (L), malic (M), and citric acids (C) applied pre-(J) or post-fermentation (W) affected microbial succession and volatiles during 56-day storage. Malic and lactic acids reduced Oenococcus abundance, but suppression of Acetobacter lasted only 42 days. Acetobacter proliferation increased acetic acid, acetaldehyde, and ethyl acetate. Lactic acid caused excessive ethyl lactate (J-L: 218.14 mg/L; W-L: 217.60 mg/L). Citric acid simultaneously lowered Oenococcus and Acetobacter, reducing bacteria by 5.00 lgCFU/mL in base wine. However, acid stress in W-C elevated acetaldehyde to 364.93 mg/L by the end of storage. After distillation, ethyl acetate remained high in W-M/L, acetaldehyde was transferred efficiently, ethyl lactate partly lost to residue, and acetic acid removed in the tail. J-C achieved the best balance between microbial control and flavor stability within 42 days, and is recommended for short-term storage (≤42 days).