I have had cheese last several months. I generally look for a color change, first white spots I see I open, remove the portions starting to mold and use as soon as possible. I just saw this about what might be the white spots you're talking about. Sounds like it might be calcium lactate. https://www.tillamook.com/faq.html#faq-72 Something to keep in mind is that the outside of the package as purchased from the store is anything but free of germs and microbes. So wash the outside of the package and after opening, wear gloves when handling the raw product so as not to transfer anything from your hands. I am not a germ-a-phobe by any stretch of the imagination. But anything you can do to minimize contamination during repackaging will extend the life of the product. Hope that helps.