Scientists have developed a system that detects whether or not milk has gone sour. The system’s made up of two parts, a small metal ribbon that’s placed inside milk containers and an in-store detector. The detector is actually a magnetic field that causes the ribbon to vibrate. If it vibrates too slowly, then you can bet that the milk has gone all sour and lumpy. Conversely, if the ribbon vibrates too quickly, you can assume the milk has been tainted with Staphylococcus aureus, which makes the milk thinner.
The system is actually fairly inexpensive and would cost less than one cent per container, but then you’d have to convince all the relevant parties to sign up.
Note that this won’t help you once the milk makes its way to your refrigerator. Once you’ve taken it home, you’d best drink it quickly, or just cut it from your diet altogether like me. No fuss, no muss.