Biodiesel Glycerin Soap (BDG) Examples

[Cinder]

I have an opportunity to get some glycerin from someone who makes biodiesel. What are some important questions to ask of him in order to make sure that the glycerin does not contain any harmful ingredients? Is there some type of testing I should do to the glycerin in order to acertain if it is safe?

 

[Saponista]

Dependent upon the process used to create the biodiesel, there may be methanol left in the glycerine. You must heat it up in order to evaporate residual methanol as it is toxic. It is also likely to contain loads of food impurities and other 'scuzz', which is going to give you a pretty ugly looking and perhaps smelling bar of soap. I'm not sure I would use this glycerine, I would use biodiesel glycerine if I bought it from a company who had purified it to an acceptable level, but not straight from the reactor.