When it comes to pears, it matters how you shop for them—whether you're cooking them or eating them—and how long you intend to store them.
While you can find a variety of pears in most supermarkets, the flavor and texture differences among them are relatively subtle. (Bosc is an exception; see below for more information.) The most important factors to consider when selecting pears are whether you’re buying them for eating or for cooking and when you plan to use them.
Since heat causes the pectin in pears—the source of their structure—to break down and soften, it’s important to cook with pears that are firm but not rock-hard. When you press the neck, it should give only slightly and feel a bit softer than a russet potato—the meaning of “firm but ripe.”
Pears for eating should yield slightly more when pressed at the neck, like a ripe avocado. Avoid pears that are soft at the base, which are overripe.
Pears that have ripened off the tree have a better texture than those that spent longer than needed on the tree. Ripening on the branch causes them to develop deposits of lignin and cellulose called “stone cells” that make the flesh gritty. To avoid this, pears are picked when immature and placed in chilled storage for anywhere from days to months. The cold storage “conditions” the fruit, allowing precursors to ethylene to form, which in turn help the pears ripen fully at room temperature with a texture that’s smooth and juicy throughout.
If pears are not fully ripe when you buy them, keep them at a cool room temperature and allow them to ripen slowly. In a pinch, you can speed up the ripening process a bit by storing the pears in a paper bag, but avoid plastic bags, which will greatly accelerate ripening and can cause them to degrade. Once the pears are fully ripe, move them to the refrigerator, where they’ll keep for up to 5 days. Whether they’re stored on the counter or in the fridge, avoid proximity to strong-smelling foods, as pears readily absorb odors.