Blue crisps hit shelves

The snack is the brainchild of family-run firm Cottage Delight, based in Leek.

The crisps are made from the Blue Congo potato, which is usually grown in Scandinavia.

The natural colour of the vegetable means that no artificial colourings are needed to make the unusual snack.

700 varieties

Cottage Delight was founded more than 30 years ago and used to sell home-made sweets.

Now the firm makes over 700 products and owns a restaurant in Leek, where chefs try out new and sometimes exotic recipes on customers.

Spokeswoman Lesley Parr said people who have tried the crisps have quickly grown to like them.

"Normally blue food isn't something you would necessarily try, but once they have overcome that initial shock and tried the product they are very surprised by the quality of the potato."