Jimmy finds out that shellfish consumed by millions have been feeding on plastic discarded in the sea, with shocking global implications. Kate finds out whether the makers of Marmite can really predict whether people will love or hate their distinctive yeast-based spread, as claimed in their latest TV advert, and Matt aims to solve the age-old mystery of how to smoothly extract ketchup from a bottle - by running across a pond of custard.

Jimmy Doherty heads to Portugal to learn about the battle against the hidden nuisance that leads to corked wine, while in Cyprus, Matt Tebbutt solves the riddle of why cooking okra produces tonnes of slime. Plus, Kate Quilton looks into the surprising difference between runny and set honey.