The present invention relates to a manufacturing process for producing a polyol from a fatty acid ester in-situ. The process does not use any added organic or inorganic acid catalyst. The polyol produced by the process is essentially free of any cation or anion. The fatty acid ester oil epoxidation and hydroxylation reactions can occur progressively in the same reactor for essentially a one-pot reaction. The polyol produced by the process is essentially free of any cation or anion. The polyol can be used to produce polyurethanes having improved properties.