Generally, the blanching time is too short and the blanching effect is too small. If blanching time is too long, water-soluble nutrients will be lost more. The blanching time of different vegetables is different. For broccoli, blanching for 3 minutes is usually enough. However, since spinach has been blanched before being put into boiling soup or wok, the heating should be stopped within 1 min to avoid overcooking and making spinach leaves soft and rotten.