Common pears, unlike their Asian-variety brethren, must ripen off the tree or, according to Oregon State University, their cores become rotted and the flesh mealy. Knowing the proper time to harvest and how to ripen the pears off the tree will provide you with a supply of sweet and juicy fruit ready for eating out of hand or using in the kitchen.
Press your thumb into the middle of the pear, and harvest when the fruit no longer feels rock-hard but more closely resembles a softball in texture. Gently twist a pear and pull it off when the stem releases from the branch. Leave pears on the tree that do not twist off without difficulty.
Refrigerate winter pear varieties such as Bosc, Comice and Anjou for two to six weeks to fully develop their internal sugars, according to Oregon State University.
Complete ripening off the tree by moving the pears to room temperature until they yield to gentle pressure, about one to two weeks, according to Texas A & M.
Ripen pears faster by placing them into a paper bag with an apple or a banana and closing the bag until the pear is fragrant and yields to gentle pressure at the stem.
Store fully ripened pears in the refrigerator for three to five days.