The Bing cherry tree (Prunus avium) was cultivated in Oregon in the 1870s. Its fruit has sweet-tasting flesh, with dark red or almost black skin when ripe. These small cherries, with a pit in the center, are delicious when they are ripe, but often the fruit sold in stores is not yet ripe. There are a few things you can try at home to hasten the ripening of Bing cherries.
Remove the cherries from their plastic bag if you purchased them at a store. The produce needs to breath, and a plastic bag, although it has holes, can still collect moisture and carbon dioxide. These two elements can cause your Bing cherries to decay.
Dry the cherries if they have moisture on them. Use an absorbent, lint-free cloth, but be careful when handling the cherries so you don't squeeze them. This can bruise the cherries and lead to rotting, not ripening.
Place the cherries inside a paper bag. Do not fill the bag until it is full. Place only one or two layers of cherries inside. Otherwise, the weight of the cherries upon themselves can cause them to bruise and rot.
Add an apple to the bag, then fold the top of the bag closed. Do not fold it so it rests against the cherries in the bag. Leave at least half the bag empty. Apples produce ethylene gas that helps speed up the ripening process of the cherries in the closed bag.
Place the paper bag out of direct sunlight. Inspect the contents daily. Remove any cherries that have ripened.
If you don't have a paper bag or you want to see the cherries, line the bottom of a low-sided box with five or six sheets of newspaper. Lay the Bing cherries in a single layer on the newspaper.
Leave the box of cherries at room temperature and out of direct sunlight on a counter or table. Check the cherries daily, and remove them as they ripen.