Expired hummus develops a sour taste.
If your store-bought hummus starts to develop a sour taste, it's probably a sign that it's gone bad, according to EatByDate.
Olive oil stops smelling like olives when it's gone bad.
"Good olive oil should smell fragrant and fruity and taste like the olives it was made from," award-winning chef Marcus Samuelsson wrote on his website.
Oil that's gone bad will often smell like motor oil or glue, according to The Daily Meal.
Bad fish starts to give off an abnormally fishy odor.
Fresh fish should be eaten within 36 hours of purchase, according to Whole Foods, EatByDate, and The Kitchn.
Fish that's spoiled will typically have a slimy flesh with a thick, slippery coating. It may also develop a fishier-than-normal smell.
Fresh vegetables turn yellow when they're going bad.
Green vegetables turn yellow when they expire.
That said, some vegetables can still be salvageable, according to the Greater Chicago Food Depository. They suggest trimming the discolored portion of veggies like celery and soaking it for 10-15 minutes in ice water to refresh.