Hello Neutral

I know that there has been some work done with Turmeric as an indicator, but I have been busy/ lazy and before I changed things in my posting I like to see these things for myself.
It occured to me that if people were successfully making biodiesel last year using Phenol Red as the indicator as per the directions in The World Famous Chopstick Titration Technique (Pat Pend) they would probably continue making good biodiesel using Phenol Red for a few more months until I could get some personal testing accomplished.

But, you have proded me into action and I present the following series of titrations.
Keeping in mind that Phenol Red apparently has a useful range of 6.8- 8.4, the titration done with it is pushed to it's darkest permanent colour instead of it's light 10- 20 second color as per phenopthalene and turmeric.

All titrations were blanked.

I purchased at great expense, 50g of ground turmeric. I then shook 2 or 3 good shakes of this into a cup about 1/3 full of methylated spirits, stired for 10 seconds and as I already had some phenol red and phenopthalene indicator I was ready to go.

For the Phenol Red titration I followed the instructions of the World Famous Chopstick Titration Technique (Pat Pend)

For the Phenopthalein and the Turmeric titration I used the instructions from the CBT Web Site

Specimen 1
Titration Value:
Phenopthalene 2.5
Turmeric 2.5
Phenol Red 2.5

Specimin 2
Titration Values:
Phenolpthalene 4.7
Turmeric 4.6
Phenol Red 4.8

Specimin 3
Phenol Red- 9
Turmeric 8.5- 9
Phenopthalein- 9

At this point I can not see a need to change my instructions and I do not have any oil titrating higher than this.

Tilly, clearly you are using your skill to overcome the inadequacy of phenol red. Others, using normal procedure have found a difference. You are pushing the titration past its proper indicated value using your judgement. If the colour does not fade in a few seconds you have overshot and there is no way of knowing how far. How would a beginner know how to judge this? The aim of the game, it seems to me, is for those who have the knowledge to remove the traps for young players where possible.

Neutral ,
If I understand you correctly , I should stop my titration as soon as the solution chnges color and fades after 15 to 20 seconds ? I have been testing oil for the past few weeks from the local fish fry house , and get an immediate change after adding just 4-5 drops . I have been treating this as 0.5 and adding 5.5 total . Am I using too much lye ? I tried one with a full .5 ml in titration and with the tumeric indicator (mixed as per your post)and it turned a deep red and stayed that way for at least two hours . This was all done with GM's 4x titration as per her book . I know this oil is very good , but was wondering if I may have a dissaster looming from using too much lye ?

Dodgeram: You are reading the instructions properly. Tumeric does not fade like the phenol based indicators. Another plus for Tumeric!

Thanks hoon !

A quick Update on comparing titration indicators

I recieved an anonymous donation in this mornings e-mail of some very thick dark WVO- No STODS classification attempted.

I ran titrations using Phenol Red, Phenopthalein and Tumeric.

For the Phenol Red titration I followed the instructions of the World Famous Chopstick Titration Technique (Pat Pend)

For the Phenopthalein and the Tumeric titration I used the instructions from the CBT Web Site

The titration results are as follows:

Phenol Red- 9
Tumeric 8.5- 9
Phenopthalein- 9

Great info.
i use phenophthalein i bought on ebay Here

but back to 25horses issues.
I can't really see where you went wrong.
Your temperature to boil off the water should be
over 212.f ..You then have to let it cool down to 135 before adding the methoxide or you will boil off the methanol.I am mentioning this only
because your post did not say it specificaly.
if your oil is really wet you have to bring it to 212 (i usually do 250) until all the bubbling and popping stops.