Tea processing full oxidation and producing "Gongfu" black tea (工夫紅茶). When there was insufficient sun and temperatures were low, the withered leaves would be processed indoors in warmed rooms and allowed to fully oxidize, then smoked dry over pine fires thus producing lapsang souchong. According to oral traditions of the region, the discovery of lapsang souchong processing was due to military troops passing through a Wuyi's tea factory during the last years of the Ming Dynasty, causing delays to tea leaf processing thus resulting in a completely oxidized leaf that the producer salvaged by drying over a fire built from pine branches.
Lapsang souchong a marketable product from these less desirable leaves. The leaves are roasted in a bamboo basket called a hōnglóng (), which is heated over burning firewood, which contributes to the dried longan aroma and smoky flavour. Pinewood is used as the firewood for lapsang souchong and imparts the characteristic resiny aroma and taste. The aroma of lapsang souchong is derived from a variety of chemical compounds. The two most abundant constituents of the aroma are longifolene and α-terpineol. Many of the compounds making up the aroma of lapsang souchong, including longifolene, originate only in the pine smoke and are not