Humans have preserved food to make it last longer for thousands of years. In this programme Ruth Alexander learns about different methods of food preservation used around the world, including pickling, dehydrating and canning.

Food historian and writer Darra Goldstein in the US explains the history of this art. Yukari Sakamoto is a trained chef and sommelier who leads food tours in Tokyo, she explains why people in Japan take the idea of a well stocked pantry seriously. And Usha Prabakaran in Chennai, India talks about her love of the Indian pickle and its role in Indian cuisine.

There are some important safety considerations if you want food to last longer, particularly if you want to store it at room temperature. There is a risk of botulism if food is not heated to the correct temperature for the correct amount of time, particularly for foods that are low in acid. Ruth hears about the laboratory testing done by Carla Schwan, Director at the National Home Food Preservation Centre based in Georgia, United States which tests recipes that can be used safely for home preserves.

Canning – storing food in glass jars and heating it – has seen a resurgence recently. Some enthusiasts refer to themselves as ‘rebel canners’, which in general refers to people wanting to use recipes other than those that have been lab tested and approved. The ‘Canning Diva’, Diane Devereaux a food preservation educator and blogger in the United States explains what motivates rebel canners, and the recipes she thinks are missing for consumers.

If you’d like to contact the programme, you can email thefoodchain@bbc.co.uk.

Presented by Ruth Alexander.

Produced by Beatrice Pickup.

(Image: a selection of foods preserved in jars of different shapes and sizes. Credit: Getty Images/BBC)

Confession and Absolution