Green beans are a type of common beans, Phaseolus vulgaris, of which both pods and seeds are eaten. Also known as string beans, French beans and snap beans, they are valued for crisp texture and fresh flavour when harvested young. Blanching before freezing preserves colour and inactivates enzymes, while thorough cooking is not the safety issue it is with kidney beans, though they are still cooked to tenderness. Graders sort them by length, diameter and straightness for fresh, frozen and canned markets.