In this episode, we discover how Britain's shoppers went bonkers for a bargain and how the supermarket price wars hotted up in the late 1970s.

By the late 70s, Britain's economic woes were worsening and shoppers everywhere were looking for a bargain, starting with the unforgettable summer of 1976. Whilst Britain sweltered in unprecedented heat, our supermarkets were in crisis, with fresh fruit and veg shortages everywhere due to the worst drought in 200 years.

We discover how 70s favourite SMASH came to our rescue when potatoes were in short supply and Dr Chris Clarke reveals how it was made and the secrets to making it so cheaply. In the kitchen, chef Rustie Lee puts SMASH to the taste test against home-made mashed potato.

We tell the story of how supermarkets battled it out with cutthroat prices and clever advertising campaigns, including the launch of the iconic ASDA price tap adverts.

Back in the lab, Dr Chris reveals how the puff is put into a sugar puff and we relive the launch of one of the most iconic advertising mascots in history, the Honey Monster, and the demise of his long-forgotten predecessor Jeremy the Bear.

We also tell the story of how the barcode was first trialed in Britain and how it revolutionised shopping in supermarkets forever, and Rustie compares prices as she attempts to make her own version of a Fray Bentos Pie .