This is a physical test. A chemical test for starch is to add iodine solution (red) and see if it turns blue/black in colour. It is possible to distinguish starch from other carbohydrates using this iodine solution test.For example, if iodine is added to an peeled potato then it will turn black.his is a physical test. A chemical test for starch is to add iodine solution (red) and see if it turns blue/black in colour. It is possible to distinguish starch from other carbohydrates using this iodine solution test.
Moving to French cuisine, one of my favourite ways of using up stale bread is in a simple Gascon soup, Garbure, made with layers of bread and cabbage, flavoured with ham, beans and vegetables. Cookery writer Kate Hill's recipe is gorgeous.
1 Let bread slices air dry for 1 to 2 hours, then cut into cubes.  In a Dutch oven, melt butter or margarine over medium heat. Cook onion and celery until soft. Season with poultry seasoning, salt, and pepper. Stir in bread cubes until evenly coated. Moisten with chicken broth; mix well.