Campaigners are calling for the ingredients of sourdough to be laid out in law. So are there too many loaves on sale that are more sourfaux than sourdough? Leyla Kazim investigates.

This programme features a visit to the Batch event at the Long Table in Stroud to meet baker and author David Wright as well as Chris Young from the Real Bread Campaign. Nutritionist Dr Vanessa Kimbell discusses how sourdough impacts on our gut health and bread historian Professor Steven Kaplan chews over whether more regulation is strictly necessary and questions how it would be enforced.

Cereal scientist Stanley Cauvain shines a light on a huge moment in British baking - the invention of the Chorleywood process - and Jules Chambe from the award-winning Wild Frog Bakehouse in Oxfordshire looks to his native France where the government did act to protect the beloved baguette.

Produced in Bristol by Robin Markwell for BBC Audio
Featuring the "Happy Knocker-Upper" 1960s Mother's Pride television advert featuring Dusty Springfield