1, the choice of pot: cook green bean soup, do not use iron pot, or cook out the probability is red. It is best to use a casserole or a pressure cooker, so that it is not easy to cook out of the red, the color will be very beautiful.

2, the choice of water: usually drink water, in fact, are alkaline, which is also very easy to make the color of green bean soup red. Then when cooking green bean soup, you can try to use pure water to cook, cook out will not change color. Or if you don't want to use pure water, you can use ordinary tap water, but when you cook it, you need to add a little white vinegar, or a little lemon juice.