• This study is the first to employ purple clay jars as containers for Baijiu storage. • Under identical storage durations, purple clay jars accelerated the development of aging-related aroma in newly distilled Baijiu. • Baijiu stored in purple clay jars demonstrated superior quality compared to that stored in ceramic or stainless-steel jars over the same period. • Isoamyl alcohol and furfural showed positive correlations with sensory attributes such as “aged aroma” and “typicality.” • Elements including iron, potassium, and zinc facilitated the formation of key flavor compounds (ethyl linoleate, ethyl hexanoate, ethyl octanoate) and aging aroma-related compounds (furfural, isoamyl alcohol). The production of high-quality Sauce-flavor Baijiu is critically dependent on storage, with the container type being a key factor. However, the scientific basis for the empirical superiority of purple clay jars over common containers like ceramic jars remains unclear. This study therefore focuses on the 0-6 month storage period of newly distilled Sauce-flavor Baijiu, the core window period from new liquor maturation to the first blending in the industry standard process, and analyzes the dynamic rules of sensory properties, flavor compounds and metal migration during its initial aging. Results showed Sauce-flavor Baijiu stored in purple clay jars was superior to that in ceramic jars and significantly superior to that in stainless steel tanks. Physicochemical analysis indicated purple clay jars induced a more pronounced decrease in total acid and pH level first drops, then rises, and then drops slightly, but the fluctuations are more pronounced, indicating a more reactive environment. Flavor analysis revealed these samples had the highest total content of flavor compounds and significantly increased odor activity values (OAVs: defined as the ratio of the concentration of an odorant to its odor threshold) for key esters, alcohols, and aldehydes. Orthogonal partial least squares-discriminant analysis identified 21 key differential compounds. Both correlation and redundancy analyses indicated that compounds such as isoamyl alcohol and furfural were positively correlated with sensory attributes including “aged aroma” and “typicality.” Meanwhile, iron, potassium, and zinc facilitated the formation of key flavor compounds (ethyl linoleate, ethyl hexanoate, ethyl octanoate) and aging aroma-related compounds (furfural, isoamyl alcohol). In conclusion, storage in purple clay jars promotes the flavor quality of Sauce-flavor Baijiu. The results not only fill the research gap on the initial aging mechanism of Sauce-flavor Baijiu, but also provide direct technical support for quality control and process optimization of new liquor in industrial production.
Wang et al. (Fri,) studied this question.