Fresh spinach leaves deteriorate quickly, whether they are purchased loose at a farmers market or in sealed plastic bags. To keep spinach fresh and ready to eat, store it at the correct temperature in the ideal container in the refrigerator. Before storing it, ensure that fresh spinach leaves are cleaned of all debris and dried, with no droplets of water clinging to them. Consume them within three to five days of purchase or harvest.
In the Bag
You may store bagged spinach in the bag it was sold in, but transfer it to another container after the bag has been opened. Once opened, moisture easily enters the bag, which speeds up the deterioration of the leaves. Store spinach wrapped in paper towels -- damp or dry -- in resealable plastic bags. Kept in the crisper drawer or on a shelf in the refrigerator, it can last as long as seven days with minimal wilting.
Wraping and the Fridge
Another option for storage is to place the dry, washed spinach leaves in a paper towel-lined plastic container or salad spinner. Cover the container and place it on a shelf in the refrigerator. The hard sides of the container protect the leaves from accidental bruising, the paper towel absorbs moisture, and the lid keeps the humidity levels ideal. Stored this way, spinach leaves can stay fresh for as long as 10 days.
Temperature and Humidity
The ideal temperature range for spinach is 32 to 36 degrees Fahrenheit. Because many home refrigerators do not go as low as 32 or 36 F, store the leaves in conditions no warmer than 40 F and refrigerate the spinach within two hours of purchase or harvest. Like other leafy greens, spinach stays fresher in humid conditions -- 95 to 100 percent relative humidity.
Signs of Freshness
When fresh, spinach leaves are perky, hold their shape well and are a bright green color. While they have a soft, velvety texture, fresh leaves do not show visible signs of wilting, and have no dark spots, yellowing or discoloration. Leaves that have started to wilt can still be added to soups, stews or meatloaf, or used for dips. Throw out spinach leaves that have begun to turn slimy.