Problems Making Bio Diesel At Home - Mixed Oils & Water

If you have been searching for information on how to make biodiesel at home you will have seen many recipe's and video's. This post is concerned with when things go wrong!

Problems can occur if you have water in your oil - Heating the waste vegetable oil removes this problem, however if you are making small amounts of bio fuel in coke bottles you can end up with a soapy jelly mix like this!


Don't give up! Don't throw your fuel away - all is not lost! After all you probably spent money on methanol and other ingredients! There is a very simple way to save the biodiesel that is caught up in this jelly.

You need to wash and filter your bio fuel to remove the jelly, this is quite a time consuming process however you will see at the end the results are good clean, green bio diesel that you started out to make!

So how do we go from the horrible mess to the clean fuel? Here is a step by step guide to the problems of making bio diesel at home, it involves a lot of washing!

First I took one of the bottles and poured in distilled water like so my reaction vessel looked like this!

You can see at the top of the bottle that there is a lighter coloured liquid starting to separate out from the jelly, I turned this bottle upside down and let it stand for a few hours so the different substances had time to separate out.

We now have 3 substances in the bottle, a dark liquid at the bottom (which I now know is unwashed biofuel as well), a semi solid layer and the unwashed bio diesel layer at the top.

The two layers are two different oils that were mixed together they can both be washed and turned into bio fuel - I think the layer in the middle is soap!

First I poured off the top layer into a filter to remove any of the solid particles after filtering the problematic biofuel I put it into a fresh container to wash.

The filtered liquid is looks a great colour and does not have any solid particles floating about in it, so it is safe to wash the fuel to remove any methanol and Sodium Hydroxide from the bio diesel.


Now we are left with the stuff below the dark layer and the jelly like gunk! There were about 4 or 5 litres that I did as a test batch that came out similar to this!


The bottle was then turned upside down and the dark layer was drained off the bottom and left to stand for a while so that the mixture of liquids separated out again.


Now we have two different coloured unwashed bio diesel liquids and all that needs to be done is the wash and dry, as you would for a normal batch that did not contain jelly like gunk!