Cloistered nuns work overtime to bake altar breads, or communion wafers, for Philly papal Mass

Shown are altar bread also known as communion wafers made by Poor Clares nuns, Tuesday, Sept. 8, 2015, at the Monastery of Saint Clare in Langhorne, Pa. The nuns are helping to supply wafers for the scheduled Mass being celebrated by Pope Francis on Sept. 27. (AP Photo/Matt Rourke) (The Associated Press)

Poor Clares nun Sister Thereza pours a mixture of water and flour to make altar bread also known as communion wafers, Tuesday, Sept. 8, 2015, at the Monastery of Saint Clare in Langhorne, Pa. The nuns are helping to supply wafers for the scheduled Mass being celebrated by Pope Francis on Sept. 27. (AP Photo/Matt Rourke) (The Associated Press)

Poor Clares nuns Sister Holy Spirit, right, and Sister Isabel prepare the oven surfaces to bake altar bread also known as communion wafers, Tuesday, Sept. 8, 2015, at the Monastery of Saint Clare in Langhorne, Pa. The nuns are helping to supply wafers for the scheduled Mass being celebrated by Pope Francis on Sept. 27. (AP Photo/Matt Rourke) (The Associated Press)

A group of cloistered nuns has been working overtime in the kitchen to help Philadelphia church officials prepare for Pope Francis' visit.

Religious sisters at the suburban Monastery of St. Clare recently made 100,000 communion hosts for the pontiff's outdoor Mass on Sept. 27.

The sisters known as Poor Clares help support themselves by baking the wafers, also called altar breads. They have about 200 customers across the U.S. and Canada.

It took two months of working extra shifts to fill the papal order. Other groups are supplying additional hosts for the Mass, which could attract up to 1.5 million pilgrims.

As an enclosed community, the nuns don't leave the monastery except for medical reasons. But sisters say the archbishop gave them permission to attend the pope's Mass.