How do you test for starch?
The most used test for starch is iodine.
Iodine forms a dark-blue complex with starch, at normal temperatures. Usually the iodine is dissolved in a solution of potassium iodide (
Sometimes it's dissolved in alcohol.
Use an iodine solution.
Iodine is an effective tool to test for starch. At normal conditions, it is usually brown, while in the presence of starch, it turns blue-black. See this picture of the test: