Fat-oil mixture after melting at 55 deg C. 3. All fuel should be this clear after the second stage.
Solid fat seems to produce a touch darker biodiesel.
The process increases yields dramatically. Use it as your standard method. The soaps diminish the yield because they bond the methyl esters to water. The bonded esters get washed out at the washing stage but make water separation more difficult and increase water consumption. This process takes care of the free fatty acids.