Scientists at the University of New South Wales in Australia have developed a method of accurately determining if milk has gone bad by using a smartphone. A new smartphone sensor called VibMilk captures the response to the vibration produced by the smartphone’s motor as it passes through the milk and then uses machine learning algorithms to analyze the signals and classify the spoiling milk at 23 different pH levels. Contrary to popular belief, "best-by" and "use-by" dates can’t accurately predict when milk will go bad, since it depends on a series of factors like storage, transportation conditions, container insulation, etc. Milk kept at correct temperatures can still be good a couple of days before its use-by date, whereas improper conditions can cause it to go bad before the expiration date. That’s why it makes more sense for users to check the freshness right before consumption to avoid unnecessary discarding or food poisoning. You can smell or taste if milk is off, but that requires opening the container, while VibMilk is non-invasive, which means you can test the freshness of the milk without breaking the seal.
