The refreshing and crisp cucumber is among the healthiest vegetables you can eat. Although comprised primarily of water, cucumbers have Vitamins A and C, and folic acid. Cucumbers also contain no fat, have very little carbohydrates and are an excellent source of silica, which is a mineral that helps to strengthen connective tissue. This is the reason why cucumbers are effective for relieving facial skin problems such as eye puffiness and sunburn. When bringing home cucumbers from the store, they must be refrigerated to stay fresh, where they will last for roughly one week.
Look at the cucumbers. If the cucumber has any signs of mold, it's rotten and should be thrown out. Do not just discard the skin. Mold on high moisture vegetables such as cucumbers can also be contaminated underneath the skin as well.
Touch the cucumber. Fresh cucumbers will be firm and rigid to to the touch. Cucumbers that have gone bad will be soft and bendable.
Slice the cucumber. The cucumber flesh should be firm and crispy, aside from the seeds in the middle. If the flesh is mushy or really soft to the touch, the cucumber is old and should be discarded.