The secret way to ripen them is in the bag
If you love a good peach half as much as I do, it's important to know that the fruit suffers sorely if put in the refrigerator before it's ready to eat.
It took Carlos Crisosto, a University of California at Davis pomologist, 30 years to find out why.
Peaches and nectarines harvested mature but hard, held at about 32° (recommended for commercial storage and shipping), then ripened at 51° to 77°, were bursting with juice and flavor. In the refrigerator or kept at a temperature up to 50°, the same kind of fruit, when "ripened," changed color and felt softer, but was mushy, cottony, and tasteless.
What to do? It's almost too easy. Pop underripe fruit (with hope that it hasn't been subjected to the danger zone) into a paper bag, fold the bag shut, and leave on the counter until the fruit gives slightly when gently squeezed, usually one to three days. If the temperature is over 80°, find a cooler spot or you'll run into other problems. You can keep ripe fruit in the refrigerator a few days more.