Look for signs like a slimy texture, foul odor, or significant discoloration (yellowing or browning) to determine if spinach has gone bad. Discard if any of these are present.
Determining if spinach has gone bad involves a few key sensory checks. First, examine the texture. Fresh spinach should be crisp and firm. If the leaves feel slimy or mushy, it's a strong indicator of spoilage. Next, give it a sniff. Fresh spinach has a mild, earthy smell. A foul, ammonia-like, or generally unpleasant odor suggests bacterial growth and that it's time to toss it. Finally, check the color. While some wilting is normal, significant yellowing or browning of the leaves means the spinach is past its prime. Small dark spots are usually fine, but widespread discoloration is a warning sign. If you observe any combination of these signs, it's best to err on the side of caution and discard the spinach.
To extend the shelf life of your spinach, store it unwashed in a breathable container lined with paper towels in the refrigerator. The paper towels absorb excess moisture, which helps prevent spoilage.