Here's How To Tell If Ground Coffee Has Gone Bad - Tasting Table
Briefly

Ground coffee does not expire but should be evaluated with sight and smell before use. If the coffee has no smell, taste, or shows signs of mold or insects, it is bad. To maintain optimal flavor, ground coffee should be consumed within two weeks. It is advised to store ground coffee in a tightly sealed container in a cool, dark place and not in the refrigerator. Whole coffee beans are recommended for better freshness and flavor retention, and grinding them fresh enhances the coffee experience.
Coffee grounds that have no smell or taste or have mold or insects are bad. Ground coffee doesn't really expire and is generally safe to consume if it passes the sight and smell test.
Once coffee beans have been ground, they retain their freshness and full-bodied flavor only for a short time. For the most enjoyable taste and aroma, it's recommended to use ground coffee within approximately two weeks.
It's important to keep ground coffee out of the refrigerator. Instead, it's best to store it in a tightly sealed container in a cool, dark location away from direct sunlight.
Whole coffee beans tend to be more robust when it comes to maintaining freshness over time, and grinding fresh coffee beans every morning is a real game-changer for coffee connoisseurs.
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