In order to tell if a pear is ripe, hold it in the palm of the hand like a baseball and press down with the thumb just below the spot where the stem meets the flesh; if the flesh gives way evenly, the pear is ripe and ready to eat. Pears, unlike other fruits, do not ripen on the tree and need to be picked a little before they reach maturity to undergo the process of ripening to fruition.
Commercial pears are picked slightly before they are mature and cooled down to just above freezing for a few days before being shipped. This slows the ripening process and ensures that the fruit doesn't decompose before it begins.
Once taken home from the store, pears should be stored at room temperature for a number of days before eating. During that time, the mature pears produce ethylene gas, which speeds up the process. Placing pears in a paper bag with a banana peel also helps things to progress.
Once a pear is ripe it should be eaten as the time it takes for them to go off is short. A ripe pear can be refrigerated for about five days to slow the ripening process once it is determined that it has reached its peak in the cycle.