Most grocery shops carry spinach all year, generally in a plastic bag, but seldom in fresh bunches. Choose leaves that are crisp, dark green, and lustrous, whether smooth or not (depends on the variety). Leaves that are withered, damaged, or stained black or yellow should be avoided. In addition to fresh spinach, you may get frozen or canned spinach. Choose the first over the second, which is frequently overdone and has a metallic flavor. For the best possible conservation, a few days in the fridge in a perforated plastic bag; Freezer: steam blanch for 1 to 2 minutes, drain out, and freeze in freezer bags for up to 3 months.