# How do you test for starch?

Feb 24, 2016

The most used test for starch is iodine.

#### Explanation:

Iodine forms a dark-blue complex with starch, at normal temperatures. Usually the iodine is dissolved in a solution of potassium iodide (${K}^{+} {I}^{-}$) to form the complex ion ${I}_{3}^{-}$, because iodine doesn't dissolve well in water.
Sometimes it's dissolved in alcohol.

Mar 31, 2018