To ripen your tomatoes this way, simply place a few unripe, unblemished tomatoes inside a paper bag. Don’t smush them in there; you want a little airflow so the fruits don’t mold.
Add a ripe banana, apple, or pepper to the bag and loosely seal it. Place the bag in a warm spot and the tomatoes should ripen in one to two weeks, depending on how much color they had in the beginning.
Collect only healthy, unbruised tomatoes. Find a large but shallow cardboard box (think banana boxes, cardboard trays and such).
Place the tomatoes in a single layer at the bottom, cover with a few sheets of newspaper or newsprint, add another layer of tomatoes, then cover with more sheets of newspaper.
By hanging the stem in a cooler spot out of direct sunlight, you can effectively extend your fresh tomato season by a month or more!