Evolutionary pattern of liquid-liquid phase separation in amphiphilic molecular self-assembly during the natural aging process of strong-aroma Baijiu.

This study reveals liquid-liquid phase separation (LLPS) as the evolutionary driver in amphiphilic self-assembly during strong-aroma Baijiu aging. Fresh Baijiu is a heterogeneous colloidal system dominated by supersaturated ethyl hexanoate/hexanoic acid, forming ∼38 μm LLPS droplets. Over 10 years, droplet size decreases by 73.68 %, evolving into hydrophobic-core/hydrophilic-shell structures. Raman mapping shows ethanol densification within droplets via hydrophobic interactions and H-bond reorganization, correlating with a 13.3 % free ethanol reduction and sensory mellowing. Crucially, electric field-assisted aging achieves structural/flavor equivalence to 5-6 years of natural aging in 40 days. This establishes LLPS as fundamental to Baijiu maturation, providing a physicochemical framework to optimize colloidal stability, sensory quality, and sustainable production in distilled spirits.