Hydrochars obtained from the wet torrefaction of lignocellulosic biomass have many potential applications. Due to the involvement of a water medium in this thermochemical process, wet torrefied liquid containing all sorts of valuable chemicals could be obtained. Hence, identification of compounds in the liquid medium will be essential to enhance understanding of the mechanism of the process as well as the value of the by-products. This study subjected empty fruit bunches (EFB) and oil palm trunks (OPT) to wet torrefaction at 180 and 220 ℃ for 15 and 30 min. The glucose, fructose, and 5-hydroxymethyfurfural (5-HMF) were quantified using HPLC. The concentration of glucose in wet torrefied EFB liquid was higher at 220 ℃ than that at 180 ℃ (i.e. 139.3 and 520.2 ppm at 180 and 220 ℃, respectively). Degradation could be observed at both temperatures when the residence time was increased from 15 to 30 min. On the other hand, wet torrefied OPT liquid had increasing glucose concentration at both temperatures when the residence time was increased (i.e. 280.6, 365.0, 439.4, and 670.9 ppm for 180 ℃–15 min, 180 ℃–30 min, 220 ℃–15 min, and 220 ℃–30 min, respectively). These trends could be attributed to the higher cellulose content of OPT relative to EFB. Fructose was higher in concentration for both wet torrefied liquids at 180 ℃ and 30 min, while it degraded rapidly at 220 ℃. The degradation of furfural could be attributed to the formation of 5-HMF, as 5-HMF concentration increased for both wet torrefied liquids as the temperature was increased from 180 to 220 ℃. Wet torrefaction of lignocellulosic biomass is a promising pre-treatment option as it can produce solid hydrochars with numerous applications and generate valuable by-products.