The new format, called Red - which stands for Read Eat Drink - will be trialed from 8 December in a former post office in Sheffield. It will feature a new red fascia with white lettering and the interior will be revamped. The store will offer coffee, freshly baked pastries and an extended alcohol section.
"We want to do the core convenience trade very well but be better than Tesco Express in the off licence, bakery and finest food areas," said MD Neil McCormick.
The concept would be rolled out to 13 of the group's 23 stores if it proves successful.
McCormick added that he hopes to grow the group's store numbers to about 75 in the next three years with the help of the Red format.