The instructions for this experiment require materials which are difficult to find in the UK. The following instructions approximate the materials and procedure shown in the video. If you have success using these notes or have an alternative procedure please let us know using the comments page.
Natural honey is mainly made from 'invert sugar', where the sucrose molecule is broken into its glucose and fructose components. A small amount of acid (citric, ascorbic or even just lemon juice) helps break down the table sugar in the experiment in this way. Invert sugar doesn't crystallise as easily as table sugar, so it is more often used in a cooking when a pure syrup is required.
When it comes to telling which is which, natural honey contains the enzyme amylase along with a lot of other enzymes. When starch (in the corn flour) is added, and the water / honey / starch mixture is left at the optimal temperature, the amylase rapidly breaks down the starch into sugar. There is no such enzyme in the artificial honey, so the starch shows up as a positive iodine test for starch. If you over-heat the test the amylase will become denatured and stop working, so make sure you keep the solutions around body temperature.
Be careful when heating the sugar as it can get very hot. Do not taste your artificial honey unless you have used food grade materials and the appropriate cooking equipment, and DO NOT consume after you have finished the iodine test.
Source: NESTA
Date: 15 January 2008
Subject: Biology
Suitability: Over 14s Over 16s Teachers Professionals