Food testing is a key part of most food technology courses. In this concise program, with the aid of teachers and students at one of Melbourne's leading secondary colleges, we look at yeast its biology, its history, and the necessary conditions for its growth. Varying contents are used in six test tubes to show why only one of them will inflate a balloon. We also demonstrate the effect of using dried and compressed yeast in the making of bread rolls in a real-life school laboratory environment. Students are also shown how to write up the result of the tests. Our teacher-consultant, Gail Major, has been declared Victoria's 1998 Teacher of the Year, so we're very proud to have Gail's involvement in this quality production.