Transfer 40 ml of ready-to-use formula or fluid milk to a 100-ml digestion flask containing a
stirring bar. For saponification, add 10 ml of ethanolic pyrogallol solution (i.e., 2% (w/v)
pyrogallol in 95% ethanol) and 40-ml ethanolic KOH (i.e., 10% (w/v) KOH in 90% ethanol).
Wrap the flask in aluminum foil and stir at room temperature for 18 hr, or at 70◦
C using the reflux vessel as depicted in Fig. 11-1. Dilute to volume with ethanolic pyrogallol solution.