questions in the title

I'd assume not but it probably has some in it

Yes, in a nutshell, BTO is a a mixture of fatty acids with some leftover gunk.





Fat is mostly made up of triglicerydes.

A triglyceride molecule is glycerol with three long fatty acid chains stuck to it.

Different fats have different fatty acids attached to the glycerol, and in different proportions.

During rotting/fermenting, trigycerides are taken apart and the leftovers float freely. This means that decomposed fat (and BTO is decomposed fat) is normally made up of various fatty acids and some glycerol, plus some other oxidation products.

To make it more visual:



glycerol :



common fatty acids:




fat (triglyceride):