Scalding beans for too long will make them hard, lose their own taste and look bad. Generally, beans can be added after the water in the pot is boiled, and it takes about five minutes to blanch. If you can add a little salt or vinegar to the water, the beans will turn green. If you can't grasp this degree, you can take a bean and take a bite when you feel almost the same. It means you can take it out immediately and cool it in cold water.

Bean, an annual climber of cowpea in Leguminosae, is 2~4 meters long. Pods droop and swell when tender, and tender pods are used as vegetables. According to the color of pods, the varieties can be roughly divided into four types: white-skinned species (light green), green-skinned species, red-skinned species and striped species. Seeds kidney-shaped, 8~ 12 mm long.