老沙头从怀里拿出一瓶老白干，咕嘟，地调了一大口。
He pulled out a bottle of wine and took a swig .
初步弄清了老白干香型白酒酒醅发酵过程中主要微生物和酶活力的变化趋势。
The change trend of enzyme and microbe in the fermented grains during the fermentation was made clear .
老白干