Dan Saladino explores the taste and temptations of sourness, from our evolution to the way we cook and eat. A story of puckering pickles, science, fermentation and edible ants.

It's only in recent times that we have understood how and why we experience the sensation of sourness. The leader in the field is EMILY LIMAN, Professor of Biological Sciences at University of Southern California in the USA. She explains the recent discoveries about what happens when we put something sour in our mouths.

Forager Miles Irving takes Dan on a wild walk through a field in Kent in search of sources of sourness from insects to red berries.

Chinese food expert Fuchsia Dunlop whose new book Sichuan Cookery, focuses on the food of southern provinces explains the role of pickles and vinegars.

In the studio Mark Diacano gives a guide to bringing more sour back into your life with lessons in piccalilli making and a beginners guide to kombucha.

Produced and presented by Dan Saladino.