The Central Kitchen business will supply a 24-hour sandwich stall under the name Healthy T, catering for a potential 65,000 campers at the festival, which will be held at Balado Park, just 20 miles from David Sands' head office and new factory in Kinross.
Central Kitchen, which is being run separately from David Sands' main business, was opened in storage space above the Kinross store, at a cost of £50,000.
It is currently supplying 12 of David Sands' 26 stores with a range of 16 sandwiches, eight salad pots and six tortilla wraps.
The food-to-go range, which is branded with David Sands' Eat Fresh label, will be rolled out to the rest of the Sands estate over the next few weeks. Previously, some stores made sandwiches on site, while others were supplied by other businesses.
Food-to-go only accounted for 3% of sales in some stores, said chief operating officer Ewen Chisholm. However, the initiative was expected to double the category's sales, he added.
Within a year, Central Kitchen will also produce chilled ready meals such as pizza, take-home salads and pasta dishes. "This should really set our fresh offer apart from the opposition," said Chisholm. "We can control what we make and when we deliver it. By giving these products more prominence in store, we will be able to boost sales too. The ready meals are also exciting, but we want to get the sandwich business up and running first."