AOAC Official Method 935.57 Acidity (Total) of Food Dressings

Titrimetric Method
First Action 1935
Final Action

Weigh ca 15 g test portion into 500 mL Erlenmeyer, dilute to ca 200 mL, and shake until all lumps are thoroughly broken up. Titrate with 0.1M NaOH, using phenolphthalein, and calculate as CH3COOH. To recognize end point, have duplicate sample at hand so that, by comparison, first change of color may be noted.