I posted this a number of years ago on the infopop forum but that forum is running down and no one is maintiaining it in a meaningful manner so hyperlinks no longer work there.

The World Famous Chopstick Titration Technique (Pat Pend)
Titration is a simple test to determine how much NaOH/KOH is required to neutralize the FFA's in the oil. This amount of NaOH/KOH is added to the Methanol as an extra amount beyond what is required to perform the reaction.

With ideas unashamedly borrowed from several different people whom I will gladly share all my royalties with on this Patent just as soon as they send me a one-time registration fee of $1000 US.

Please Note
I have written this procedure for titrations using NaOH.
If you are going to use KOH in the reaction, just substitute KOH for the NaOH in the directions.
Also change the base amount from 5g NaOH to 7g KOH adjusted up if the purity is less than 99%.

Please Note
During the titration, depending on which alcohol you use, the oil might NOT disolve into the Alcohol. That is fine, all the alcohol is doing is washing the FFA's out of the oil.

MATERIALS NEEDED

ALCOHOL
1- bottle of isopropyl alcohol (isopropanol).

In the USA, Iso-HEET® Premium Fuel System Dryer & Antifreeze, 12 fl. oz. in the red bottle is available at all fine auto shops and is about 99% isopropyl alcohol. $2.00.
Also, in the USA rubbing alcohol is Isopropyl alcohol 70% purity will work fine.
OR
1- bottle of Ethyl Alcohol (Ethanol).
In Australia and many other countries, "methylated spirits", commonly called "Metho" is 95% Ethanol and only about $2 a litre.

1 Box Flat Wooden Tooth Picks

INDICATOR
1 container of Ground Turmeric

Turmeric is a spice and is readily obtainable from all Fine Grocery Stores.
OR
1- bottle of Phenol Red

Phenol Red is normally used to check the pH of swimming pools, is a liquid, and is easily available from all fine Pool Shops.
OR
1- bottle 1% Phenolpthalein indicator

Good luck finding it.

1-litre of "Titrating Fluid"
"Titrating Fluid" is made by dissolving 1g NaOH into 1 litre of distilled or Rain Water. In a pinch, tap water will work too.
As you might not have particularly accurate scales, one way of achieving this is to measure out 10g NaOH and dissolve this into 1 litre of distilled or rain water.
Now take 100ml of this water and mix with 900ml distilled or rain water.
You now have pretty close to the 1g NaOH in 1 litre of distilled or rain water.
Or, go to your local pharmacist or High School Science Dept and ask them to do the measuring for you.

EQUIPMENT NEEDED

1- 50ml medicine measuring cup with ml graduations marked on the side. The tapered ones are best. From local pharmacy

1- glass 1 ml eyedropper with graduations marked on the side. From local pharmacy

1- 3ml Syringe (no sharp) From local pharmacy

1- plastic chopstick From local chinese restaurant.

Total equipment cost should be under $10 and is good for hundreds of titrations.
No fair counting the cost of a meal at your favourite Chinese shop to steal a chopstick.

Be aware that because Phenol Red, Turmeric and phenolphthalein all change colours at a different pH, a slightly different titration technique is required with each one.

THE PROCEDURE USING PHENOLPTHALEIN

1. Pour about 10ml of room temp alcohol (Isopropyl or Ethanol} into the 50 ml medicine measuring cup.

2. Place 3 or 5 drops of Phenopthalein into alcohol

3. Fill the syringe with "Titrating Fluid" and while using the chopstick to vigorously stir, slowly, drop by drop, add "Titrating Fluid" to the alcohol until the alcohol just starts to turn a permanent pink colour and then STOP.
You have just performed the "Blank Titration" The "Blank Titration" neutralizes any acid that may be in the alcohol.
You are now ready to titrate the oil in question.

4 Using the eyedropper, add exactly 1ml of the oil to be titrated to the alcohol.

5. Place into microwave oven and microwave until the First Bubble appears (5 or 10 seconds)STOP Note: This step is not absolutely necessary.

6. Now, always filling the syringe with exactly 3ml of "Titrating Fluid", start dropping the "Titrating Fluid" into the medicine measure while stirring vigorously with the chopstick.
I find an up and down motion which breaks the oil up against the bottom of the medicine glass works best.
Do not stop stirring

7. Keep track of how many ml of "Titrating Fluid" is needed for the liquid to turn and remain a light pink for about 20 seconds before the colour fades..

This is your titration number which you then add to 5 to find out how many grams of NaOH is needed per litre of WVO.

It takes longer to read it than to do it.

THE PROCEDURE USING TURMERIC

1. Pour about 10ml of room temp alcohol (Isopropyl or Ethanol} into the 50 ml medicine measuring cup.

2. Scoop out a small amount of Ground Turmeric on the wide end of a toothpick.
Put the turmeric into the alcohol and use the Chopstick to stir it well into the Alcohol for about 5 seconds.
The Alcohol should now be a nice yellow colour.

3 Fill the syringe with "Titrating Fluid" and while using the chopstick to vigorously stir, slowly, drop by drop, add "Titrating Fluid" to the alcohol until the alcohol just starts to turn a permanent pink colour and then STOP.
You have just performed the "Blank Titration" The "Blank Titration" neutralizes any acid that may be in the alcohol.
You are now ready to titrate the oil in question.

4 Using the eyedropper, add exactly 1ml of the oil to be titrated to the alcohol.

5. Place into microwave oven and microwave until the First Bubble appears (5 or 10 seconds)STOP Note: This step is not absolutely necessary.

6. Now, always filling the syringe with exactly 3ml of "Titrating Fluid", start dropping the "Titrating Fluid" into the medicine measure while stirring vigorously with the chopstick.
I find an up and down motion which breaks the oil up against the bottom of the medicine glass works best.
Do not stop stirring

7. Keep track of how many ml of "Titrating Fluid" is needed for the liquid to turn and remain it's darkest red for 20 seconds before the colour fades..

This is your titration number which you then add to 5 to find out how many grams of NaOH is needed per litre of WVO.

It takes longer to read it than to do it.

THE PROCEDURE USING PHENOL RED

1. Pour about 10ml of room temp alcohol (Isopropyl or Ethanol} into the 50 ml medicine measuring cup.

2. Add 3 to 5 drops of phenol red to the alcohol.

3 Fill the syringe with "Titrating Fluid" and while using the chopstick to vigorously stir, slowly, drop by drop, add "Titrating Fluid" to the alcohol until the alcohol just starts to turn a permanent pink colour and then STOP.
You have just performed the "Blank Titration" The "Blank Titration" neutralizes any acid that may be in the alcohol.
You are now ready to titrate the oil in question.

4 Using the eyedropper, add exactly 1ml of the oil to be titrated to the alcohol.

5. Place into microwave oven and microwave until the First Bubble appears (5 or 10 seconds)STOP Note: This step is not absolutely necessary.

6. Now, always filling the syringe with exactly 3ml of Titrating Fluid, start dropping the Titrating fluid into the medicine measure while stirring vigorously with the chopstick.
I find an up and down motion which breaks the oil up against the bottom of the medicine glass works best.
Do not stop stirring

7. Keep track of how many ml of "Titrating Fluid" is needed for the liquid to turn and remain its deepest, darkest purple/ red for at least one minute.

This is your titration number which you then add to 5 to find out how many grams of NaOH is needed per litre of WVO.

It takes longer to read it than to do it.

While I am assured that the Turmeric Titration is more accurate than using Phenol red, and phenolpthalein is more accurate still, tests I have performed shows that Both Turmeric and Phenol Red give virtually identical titration results and are also virtually identical to the results obtained when using Phenolphthalein.
__________________
Saint Tilly