Season 21 - Episode Guide

In a two part special, chef Paul West, dietician Professor Clare Collins and chemist Dr Noby Leong reveal the delicious chemistry, biology and physics hidden inside the foods we love, so we can cook better and eat healthier.

Paul explores the science behind cryogenic freezing and how it's being used to ensure frozen fish tastes almost as good as fresh. In a gelato factory, Clare gets the scoop on why humans are hard-wired to desire junk food.

Catalyst sets up a pop-up dental clinic in Western Sydney to investigate Australia's most common dental complaints, uncovering the tips to keep your mouth healthy and revealing surprising secrets behind a beautiful smile.

Asteroids are an ever-present threat to our survival, but as Astrophysicist Professor Tamara Davies discovers - they may also be responsible for kick-starting life on Earth.

As our populations grow, cities are under increasing pressure. Physicist Dr Niraj Lal explores engineering solutions designed to make our cities cleaner, greener and more efficient places to live.