Updated: Oct 6, 2020
Finding out if eggs are fresh is actually fun and is something that you should even do with expired eggs. Sometimes, they’re still good and this test will avoid food waste and save money. Amazing describes my favorite kitchen trick, if they sink, they are good eggs.
If you spot mold on cheese, it's generally safe to cut off the moldy part and eat the rest, spores likely will not have spread throughout the cheese. As well as if the cheese has hardened and slightly transparent, you can cut that off. Another sign that a cheese has gone bad is a smell or taste of spoiled, sour milk.
Butter can definitely go bad, though only if left out or kept in the fridge for a really long time. Like 6 months longer than the date on the package (and even, then, it’s worth checking to make sure because it might still be good). They go bad much faster when left out at room temperature.
Fruit & Vegetables
If your fruit/vegetable has become mushy, grainy, or even sprouted, it's probably a sign that you shouldn't eat it, according to the Greater Chicago Food Depository. Other warning signs that a fruit has gone bad include extreme discoloring, foul odors, or wrinkly skin that's peeling away.
Visible signs of mold or white, black, blue, or green spots on the bread are a sure sign it has spoiled and you should discard it. If your store-bought bread smells sour (like vinegar), yeasty, or even like alcohol, get rid of it too.