A question for Jan regarding the 3/27 test

[Julian]

Jan, you'll probably regret signing up on here because you're going to get idiots asking all sorts of stupid questions.   I'd like to take the opportunity of being the first idiot!

There is something that's been bugging me about the 3/27 test for some time to the point where I found a copy of your email to the Journey to Forever people and copied it to our wiki to show the extent of the test as you originally described it  ...  http://www.biopowered.co.uk/wiki/3/27_test

In nearly ten years of making biodiesel and something in excess of 180 batches, I've only three times had what I'd consider a "clear" 3/27 test pass.  My definition of clear being colourless, crystal clear methanol with no oil drop out.

I usually get either a clear (i.e. transparent), but straw coloured result with no oil drop out or a cloudy (i.e. opaque) and straw coloured result with no oil dropout ... both of these I consider to be acceptable.

I've heard people claim that the colour and cloudiness are indications of monoglycerides and diglycerides manifesting themselves.  As a complete know nothing when it comes to chemistry, this seems plausible to me, however, no one can quote any authoritative source as to the origin of these claims.

Can you advise if colour and/or cloudiness have any significance in this test?

[Tony]

Good question.  It does seem that the further the reaction is pushed the greater chance of a clear 3/27 result.  I always put any colouration down to feedstock variance and possible soap/glycerol in suspension from incomplete settling of a sample.  But so long as it is crystal clear and not cloudy in any way, I'm happy.

And yes, welcome to our humble site Jan, you're famous in biodiesel circles for the 3/27, that's for sure.

[Chug]

It will always take on the colour of the bio but it should still be clear and bright, but it wont go completely clear like methanol.