Requirements (Instruments, Chemicals & Other)
Butter sample
Neutralized ethanol
Sodium hydroxide solution (0.1 N)
Phenolphthalein indicator
Burette with stand
Conical flask (250 ml)
Weighing balance
Hot plate

Procedure

1. Weigh accurately 5 g of butter sample into a 250 ml conical flask.
   
2. Add 50 ml of neutralized ethanol into the flask.
   
3. Heat the flask gently at about 50°C to dissolve the butter completely.
   
4. Add 2 drops of phenolphthalein indicator to the mixture.
   
5. Titrate the hot solution with 0.1 N NaOH solution until a light pink color persists.
   
6. Note the burette reading and calculate the FFA content
   

Calculation
FFA content (% Oleic acid) = (V × N × 0.282) / W × 100

Where,
V = Volume of NaOH used (ml)
N = Normality of NaOH solution (0.1 N)
W = Weight of butter sample (g)
0.282 = Milliequivalent weight of oleic acid.