Whether purchased loose at your local farmers market or in a sealed plastic bag at the grocery store, fresh spinach leaves are known to deteriorate quickly. To combat the dreaded turning of your spinach, store it at the correct temperature in the ideal container in the refrigerator. Before storing, however, ensure that fresh spinach leaves are cleaned of all debris and dried, with no droplets of water clinging to them. Moisture is largely the enemy here, causing the awful brown, jelly-like slim to form on the spinach leaves. Follow these instructions, and you'll be able to enjoy your leafy greens within three to five days of purchase or harvest.
In the Bag
Once a bag of spinach has been opened, moisture enters easily, which speeds up the deterioration of the leaves. So go ahead and transfer the spinach to another container after the bag has been opened. The best way to do this is to wrap the leftovers in paper towels -- damp or dry -- and place in a resealable plastic bag. Kept in the crisper drawer or on a shelf in the refrigerator, spinach can last as long as seven days with minimal wilting. This method of storing spinach leaves is also great for freezing spinach if it was bought in bulk and there is too much to eat before it will go bad. When stored properly in the freezer, spinach leaves will keep for up to two months without negative affects to the taste and texture. The nutrition vitamins in spinach, however, will slowly leech out the longer the leaves remain frozen.
Another option for storage is to place the dry, washed spinach leaves in a paper towel-lined container or salad spinner. Cover the container and place it 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 balanced. Placing a dry paper towel in with the leaves is quite helpful for wicking away excess moisture as well. 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. Since many home refrigerators don't go as low as 32 or 36 degrees Fahrenheit, you should store the leaves in conditions no warmer than 40 degrees Fahrenheit and refrigerate the spinach within two hours of purchase or harvest. Avoid excessively warm settings to prevent the spinach leaves from wilting. Like other leafy greens, spinach stays fresher in humid conditions -- 95 to 100 percent relative humidity.
Signs of Freshness
Fresh spinach leaves are perky, hold their shape well and are a bright green color. While they have a soft, velvety texture, fresh leaves don't 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, meatloaf, smoothies, wilted in a pan, added to omelets or used for dips.
Throw out spinach leaves that have begun to turn slimy and brown. At this point, the taste and texture of the spinach leaves have fallen to a point beyond pleasurable consumption.