Salt has been a staple ingredient in cooking and preserving food for thousands of years.

It adds flavour to food, preserves it, and keeps our bodies functioning.

In recent years, gourmet brands have emerged and some consumers have been willing to pay higher prices for rock and sea salts.

Ruth Alexander finds out how this trend started and asks whether there’s anything special about speciality salts.

She speaks to Jess Lea-Wilson, Ronan Burns and Rob Jardine about how Halen Mon seasalt is made in Anglesey, Wales; Craig Cormack, ‘The Salt Chef’, about the salt tasting sessions he runs in South Africa; and Rajesh Shah of Vikas Center for Development about how technology is improving conditions and profits for salt workers in the Indian state of Gujarat.

If you would like to get in touch with the programme, email thefoodchain@bbc.co.uk.

Presented by Ruth Alexander.

Produced by Julia Paul.

(Image: a spoonful of salt. Credit: Getty Images/BBC)