Three protein hydrolysates (HVPs) were produced from untoasted defatted soy by acidic hydrolysis (aHVP), enzymatic hydrolysis (eHVP), and enzymatic hydrolysis followed by a heat treatment with glucose (eHVPrea). The three HVPs were characterized by amino acid analysis, identification of volatile compounds, and sensory profiling. aHVP had a higher degree of hydrolysis compared with eHVP and eHVPrea which still contained peptides composed mainly of the smaller and the acidic amino acids. A total of 29 volatile compounds were identified by GC-MS. Furans and sulfides were primarily found in the acidic HVP, while alcohols and pyrazines primarily were found in eHVP/ eHVPrea. Further Maillard reaction had occurred in eHVPrea compared to HVP, but the sensory profile was not altered. The multivariate analysis of the sensory profile showed that the acidic HVP had increased intensity in the bouillon, soy, and lovage odor and taste characteristics compared with the two enzymatic HVPs.