UNITY, Maine — Few college campuses, if any, have root cellars to store their fruits and vegetables.

But Unity College is going back to the time-tested method of keeping produce fresh. The environmental school in central Maine on Friday will hold a ceremony and tour to mark the completion of a root cellar.

A root cellar is a traditional underground structure used to store vegetables and fruits. Because it’s buried, the temperature and humidity are regulated. Unity’s root cellar combines old-fashioned earth tempering with state-of-the-art control systems that automatically draw in cool nighttime air.

Unity’s root cellar was built with student volunteer labor under the guidance of the college’s sustainability staff and instructor Jim Merkel of Belfast, who teaches an environmental citizen course.