A simple, convenient kit was developed to measure titratable acidity (TA) of milk in farm bulk tanks. The kit was based on the con-ventional determination of TA with standard base and phenolphthalein. Glass tubes were calibrated to contain a calculated amount of milk and base to show the phenolphthalein endpoint up to a chosen TA level. Samples remaining white would be rejected as TA above the chosen level. A survey using the kit and standard TA titration was carried out in winter and summer on manufacturing and Grade A milks. In 192 samples, TA averaged 0.164% and ranged from 0.11 to 0.31% TA with a standard deviation of 0.021% TA. There was no difference from grades or seasons. The kit test failed on only four samples. Lactic acid content of milk was measured in selected samples by an ether extraction-gas chromatographic method. Good agreement was obtained between the method and added and/or developed acidity determined by titration. Fresh milks with varying TA were shown to contain no lactic acid
