Tiu Yuen Soy and Food Factory in Kwu Tung Yin Liu area of Sheung Shui. Soy extracts from fermented bean mixture was put under the sun to thicken.上水古洞煙寮區的調源醬油食品廠內，將發酵後提煉的豉油，置於陽光下曬曝以提升濃稠度。