Left wine-vessel radical — pictograph of a tall narrow-necked jar used for fermenting wine and vinegar. Anchors
酸 in the fermented-liquid family alongside
醋 (vinegar),
醉 (drunk),
酒 (alcohol),
酱 (sauce),
醇 (mellow wine). Sourness is the taste of fermentation gone past its peak, hence the wine-jar radical.