The standard reaction to produce biodiesel is run at about 130 deg F (55 deg C), and mixed for at least one hour. Additional heat helps the reaction proceed; however it is important to keep the reaction under the boiling point of methanol (148.5 deg F = 65 deg C), unless the reaction is contained in a safe pressurized vessel. If mixing is vigorous, the reaction may be close to complete after just a few minutes, with the liquid becoming dark in color, but most people allow the reaction to go longer to be sure it is as complete as possible. There is no harm in allowing the reaction to mix for several hours or overnight if convenient. The idea is to convert as many triglycerides to FAME as possible. If conditions are not optimal in terms of temperature, amount of mixing, time, percent methanol (22% recommended), and proper amount of catalyst then partial products may form, such as diglycerides or monoglycerides. The presence of these partial products may not be evident, although there are some simple quality control tests which can be done.