Volatile compounds sorption during the aging of Chinese Liquor (Baijiu) using Pottery Powder

Pottery jar is the preferred storage vessel for aging baijiu, Chinese liquor, and it could sorb liquor micro-compounds. The objective of this work was to identify the sorption of liquor micro-compounds onto pottery powder, and gained insights regarding the sorption processes and mechanism. The sorption of liquor micro-compounds onto pottery powder of different sizes was studied using different kinetic models. The results showed that the sorption capacity varied among particle size of pottery powder, which also affected equilibrium time. The sorption process could be well described by the pseudo-second-order model, and the external diffusion was the rate-limiting step. Liquor volatiles in pottery powder at equilibrium were characterized, which detected alcohols, esters, acids, and furan by gas chromatography–mass spectrometry (GC–MS). These findings demonstrated pottery could not only cause subtractive changes that occur to liquor during the aging period, but also as a vector for transferring aromas sorbed when reused.