The green bean, also called cornetto and mangiatutto bean, is a variety of bean belonging to the Leguminosae family, which is harvested when still not fully ripe. The characteristics of this plant are very similar to those of the bean and so is its cultivation. However, its pod is thinner than the normal bean and can be green or yellow, straight or curved.

It is a typically summer vegetable (until October in the temperate climate regions), although today, with the new methods of conservation, it can be found on the market all year round. The best time to harvest the green bean is when the pod has a diameter of less than one cm: at this stage it is still devoid of the "thread", the thin fibrous line that runs along one of the ribs of the pod.

Green beans are consumed only cooked, after removing its ends; once the leathery thread along the pod had to be removed, but with modern varieties this is no longer necessary. In the fridge they last about 4-5 days but they can be also frozen for up to 3 months, raw or blanched and already cleaned. They are refreshing and low in calories (20 calories per hectogram, compared to 130 or more for other legumes). Moreover, they should be lightly cooked otherwise they become hard.

Among the most common varieties of green beans we remember the «Bobis», the «Contender», the «Marconi», all with green pods; the «Butter of Rocquencourt» and the «Wonder of Venice» with yellow pods. Yellow beans can be tubular or slightly flattened and have a delicate taste. For this reason it is good to combine them with ingredients of not too intense flavour. String beans are tasty and very thin, reaching 50 cm in length.

There are also two varieties with violet pods: the «Re dei Bleu» and the «Triumph Violet». To make sure that the green beans are fresh you need to detach one of the ends which will have to break cleanly, even emitting a drop of moisture. If they fold without breaking, they are old.